When we are in the carriage, we notice a sign on the door saying "Don't lean!". For what do we need such a reminder? To control the number of people in the carriage. If someone leans on the door, it means that the carriage is overcrowded. In case of some accident, doors may open during the movement of the train. At the train driver's room there are special detectors that indicate that a person has leant on the door. So, the train may stay longer at the platform to avoid injuries.

Задание

Choose the correct option

When we are in the carriage, we notice a sign on the door saying "Don't lean!". For what do we need such a reminder?

To control the number of people in the carriage. If someone leans on the door, it means that the carriage is overcrowded.
In case of some accident, doors may open during the movement of the train.
At the train driver's room there are special detectors that indicate that a person has leant on the door. So, the train may stay longer at the platform to avoid injuries.