What does a sign with a picture of a person on a skateboard indicate?

Answer: B — No skateboarding allowed.

A sign with a picture of a person on a skateboard typically indicates that skateboarding is not allowed in a certain area. Option A may seem like the correct answer since it mentions skateboarding, but it is referring to an area where skateboarding is allowed. Options C and D are unrelated to skateboarding and do not have any indication of a person on a skateboard, making them incorrect. Therefore, the correct answer is B.