Horatio Is Asked What Main Dish Was Served for Lunch

Horatio is asked what main dish was served for lunch at the cafeteria yesterday. He knows that it was roast beef, but before responding, he observes six other students who say the main dish was pizza. Horatio is most likely to say the main dish was pizza if he hears the response from

A) the six other students in three pairs of two.
B) all the students at once.
C) the six students at six different times in six different places.
D) the six other students in two pairs of three.