What is a taxi cab roof-sign?

1. A box in which the taxi meter is placed, and which must be lighted while the taxi is driving.
2. A device that registers the details of the bus ride on a disc.
3. A box used for storing a first aid bag.
4. Correct answer: A device installed on the roof of a taxi cab, which can be lighted, and is used for identification purposes.

WhyThe taxi roof sign is a device on the roof that can be lit and is used to identify the taxi. It is not the meter inside.