How many seconds in advance should you signal before making a turn?

Answer: C — 4 seconds

You should signal at least 4 seconds before making a turn. This gives the drivers behind you enough time to slow down and prepare for your turn. Option A, 5 seconds, may seem like a good choice, but that is the minimum amount of time required for signaling on highways. Option B, 2 seconds, does not provide enough time for other drivers to react and may lead to accidents. Option D, 6 seconds, is also not optimal as it may confuse other drivers and cause them to expect a turn that is not approaching yet. Therefore, option C, 4 seconds, is the best choice for signaling before making a turn.