You interview your family members at a picnic and record their ages and shoe sizes. The data is shown in the table. Which number describes how widely spread out their ages are?
A) 10
B) 12
C) 17.9
D) 37
x (age) y (size)
8 7
9 8
10 9
8 9
14 9
15 11
10 10
33 9
27 9.5
45 10.5