All passenger vehicles must be equipped with
a. a rear-view mirror.
b. two windshield wipers
c. both a & b

The answer is C. All passenger vehicles must be equipped with both a rear-view mirror and two windshield wipers.

According to the New York Department of Motor Vehicles, every vehicle must be equipped with a mirror that enables the operator to view the road behind it. According to such Department, every vehicle also has to have suitable wipers that clear the windshield enough for the operator to have a clear vision.  

This Department also states that vehicles must have other accessories such as a horn and safety belts; all of these accessories are mandatory and are thought to preserve the safety of the operator, the passengers and the other vehicles.