In a road tunnel, it is not allowed to turn the vehicle, reverse the vehicle in the tunnel under any circumstances.
Answers 2 and 3 are incorrect because you are allowed to turn around, reverse when necessary.
Motor vehicles and special-use motorcycles must turn on their lights; rudimentary vehicles must turn on their lights or have a light-emitting object; only stop and park their vehicles at prescribed places.
Motor vehicles must turn on the lights even when the tunnel is bright; must allow the vehicle to run in one lane and change lanes only where it is allowed; to turn the vehicle, reverse when necessary.
Special-use motorcycles must turn on the lights even when the tunnel is bright; must allow the vehicle to run in one lane and change lanes only where it is allowed; to make a U-turn and reverse when necessary.