Question

when you see any yellow sign, what should you do? prepare to respond to some increased risk change directions do not enter

Explanation:

Yellow traffic signs are warning signs, which means drivers should be prepared for potential hazards or increased risks ahead. "Change directions" is not the standard action for yellow signs, and "Do not enter" is for red or other prohibitory signs (usually red circle with a slash or specific "Do Not Enter" signs, not yellow).

Answer:

A. Prepare to respond to some increased risk