Clause 27.2 (Section 27 "Driving on Motorways and Roads for Motor Vehicles"), subclause a)

On motorways and roads for motor vehicles, it is prohibited: a) for tractors, self-propelled machines, and mechanisms to drive.

This subclause excludes the option with tractors/self-propelled machines — they are prohibited from driving on the motorway.

Clause 27.2 (Section 27 "Driving on Motorways and Roads for Motor Vehicles"), subclause b)

On motorways and roads for motor vehicles, it is prohibited: b) for cargo vehicles with a permitted maximum mass over 3.5 t to drive outside the first and second traffic lanes (except when turning left or making a U-turn on roads for motor vehicles).

This subclause confirms that cargo vehicles over 3.5 t are allowed to drive on the motorway, but with a lane restriction (not beyond the 2nd lane).

Clause 12.6 (Section 12 "Speed Limits"), subclause g)

Additional speed restrictions: e) for vehicles driven by drivers with less than 2 years of experience — no more than 70 km/h.

This clause clarifies the conditions for drivers with less than two years of experience: they are not prohibited from driving on the motorway, but a lower maximum speed is set for them.

Clause 33.5.1 — 33 "Road Signs", 5 "Information and Direction Signs", sign 5.1 "Motorway"

Sign 5.1 "Motorway" is used to indicate roads where the relevant traffic regimes are established in accordance with Section 27 "Driving on Motorways and Roads for Motor Vehicles" of these Rules. The sign is placed at the beginning of the motorway.

This sign "activates" the special rules of Section 27, including the prohibitions/restrictions of clause 27.2.

That is, the correct answer is "Answers 1 and 2.", considering that according to the definition of the Traffic Rules, driving on the motorway is prohibited for tractors/self-propelled machines (clause 27.2 a), cargo vehicles over 3.5 t are allowed to drive with lane restrictions (clause 27.2 b), and for drivers with less than 2 years of experience, only an additional speed limit of 70 km/h applies (clause 12.6 e).

When sign 5.1 "Motorway" is installed on the road, this means that a special traffic regime, defined by Section 27 of the Traffic Rules, applies further on. To answer the question "who is allowed," it is convenient to first recall who is prohibited from entering the motorway.

In clause 27.2 a), it is explicitly stated that tractors, self-propelled machines, and mechanisms are prohibited from driving on motorways. Therefore, vehicles from this list cannot travel on the motorway, and any answer option mentioning tractors or self-propelled machines should immediately be dismissed as incorrect.

Next, let's check the other proposed options. Trucks with a permitted maximum weight of over 3.5 tons are not prohibited from driving on the motorway. Clause 27.2 only sets lane restrictions for them: they are not allowed to drive beyond the first and second lanes (except for certain cases on roads for automobiles). That is, the very fact of driving on the motorway is allowed for such trucks, but with compliance to the requirements regarding their position on the carriageway.

Similarly, drivers with less than two years of experience are not prohibited by the Traffic Rules from using the motorway. There are separate speed restrictions for them, but this is not a ban on driving on the motorway itself. Therefore, vehicles driven by such drivers may travel on the motorway provided they comply with the relevant requirements of the Rules.

Thus, the correct answer is "Answers 1 and 2," since clause 27.2 prohibits tractors and self-propelled machines on the motorway, while trucks over 3.5 tons and vehicles driven by drivers with less than two years of experience are allowed to drive (with lane requirements for trucks and speed requirements for inexperienced drivers).