Question 830569
Let's look at these individually:
(B) Can a student have a negative height?  No.  The answer is not B.
(D) Students range from 6 feet to 9 feet tall.  6 feet is plausible, but is an above-average height.  9 feet is not plausible.  The answer is not D.
.
We're left with two scenarios.  Students range from 3'-7' tall, or from 4.5' to 6.5' tall.  While the first is *possible*, those heights are at the extremes.  It's much more likely that students come in with a median of 5.5'.  Therefore, while the answer COULD be either (a) or (c), (a) is less likely.  The correct answer is (C).