If you are receiving a ticket, you must sign it

Answer: C — before the officer leaves.

Signing the ticket before the officer leaves is necessary because it signifies that you have received the ticket and is required by law. Option A is incorrect because you must wait for the officer to hand you the ticket before signing it. Option B is incorrect because it is always important to read the ticket carefully before signing it. Option D is incorrect because signing the ticket does not automatically mean you are admitting guilt, but rather confirms that you have received it.