Before reaching the crest of a hill or entering a curve, you should do what?

Answer: C — Slow down, move to the right side of the road

When approaching the crest of a hill or entering a curve, it is important to slow down and move to the right side of the road. This allows you to have better visibility and control over your vehicle. Option A is incorrect because increasing your speed can actually decrease your visibility and increase the risk of losing control. Option B is incorrect because moving to the left side of the road can put you in the path of oncoming traffic. Option D is incorrect because accelerating to pass other vehicles can be dangerous in a hill or curve, as you may not have enough time or space to safely complete the pass.