List of traffic signs and their meaning

Not sure what you needed so I named a few.

Stop sign - Tells when to come to a stop

Speed limit - Tells the speed you should be going

Slow - Tells you when to slow down

RR - Tells when there is a railroad

Sign with stop lights - Tells that there is stop lights ahead.

Wrong way - tells you that you are on the wrong side of the road.

the first question's answer is a.