Walt and Hank collect quarters from different states. Walt collected q quarters. Hank collected four fewer quarters than Walt. The combined dollar value of their coins was $17.50. The following equation represents the situation.

0.25q + 0.25(q - 4) = 17.50

How many quarters does Walt have?

A.
33 quarters
B.
35 quarters
C.
37 quarters
D.
43 quarters