Which scenario is an example of understatement?

 A.The sign above the carrots in the produce section reads: "Eyesight not so good these days? Have a carrot, and it will lift the haze." B.Travis shows his Spanish test to his mother, "Look, Mom, I scored a 100, which means I can speak Spanish fluently!" C.The police officer stops a speeding driver and asks, "Sir, did you know you were going 40 in a 65 mile-per-hour zone? I'm going to need you to speed up." D.The doctor tells Juan, "Your leg is broken in three places, so you are going to be sore for a while."