X was reviewing the water bill for her dog day care and spa and determined that her highest bill, $4,600, occurred in July when she washed 500 dogs and her lowest bill, $3,200, occurred in February when she washed 175 dogs. What was the fixed cost associated with X's water bill?

A. $2,445

B. $4.31

C. $3,845.75

D. $4,600