Where is a proper place to install plates with the details of the taxi owner and of the driver?

1. On the frame-head between the doors, on the right side only.
2. Correct answer: On the inner part of the taxi’s left and right door frame-heads.
3. Both of them should be installed to the right of the dashboard, in front of the glove compartment.
4. From both sides of the dashboard.

WhyPlates with the owner's and driver's details are fixed on the inner side of the left and right door frames. That way a passenger sees them whichever side they get in.