State whether the variable is discrete or continuous.
(a) Number of cars serviced at a garage during one day
(b) Time a mechanic takes to replace a defective muffler
(c) Number of cheeseburgers a fast-food restaurant serves each day
(d) Weight of a student

(A) (a), (b) are discrete; (c), (d) are continuous
(B) (a), (c) are continuous; (b), (d) are discrete
(C) (a), (c) are discrete; (b), (d) are continuous
(D) (a), (d) are discrete; (b), (c) are continuous