Answer:
C. At an intersection with a green light or green arrow, unless a "No U-Turn Sign" is posted.
Step-by-step explanation:
In general, U-turns are not allowed in residential districts unless there is an intersection with a green light or green arrow, and there is no "No U-Turn" sign posted. However, it's important to note that traffic laws and regulations can vary by state and local jurisdiction, so it's always a good idea to check your local traffic laws and regulations to be sure.
Option A mentions visibility, which is important for making safe driving decisions but does not necessarily impact the legality of making a U-turn.
Option B mentions a traffic sign or signal protecting you, which may be a factor in deciding whether it is safe to make a U-turn, but again, the legality of making a U-turn is generally determined by local traffic laws and regulations.