The first step in this problem is ensuring you understand the terminology.

Four consecutive odd numbers is a sequence of odd numbers in the order they would appear on a number line, skipping the positive numbers. Some examples of numbers that would fit this criterion would be 1, 3, 5, 7 and -7, -5, -3, -1.

Since the sum is 72, we know that the numbers are positive.

Using the guess and check method, we might start with a number that, roughly, could be 72:
13 + 15 + 17 + 19 = 64.

That's close, but let's go up a little higher. We were off by 8.

15 + 17 + 19 + 21 = 72

Great! The last step is to take the average of the smaller three.

The average is 17 since it's in the middle and they are equidistant from each other. You could check this by doing (15 + 17 + 19)/3.

Therefore, the answer is (C) 17.