An office machine purchased new for $3,600 loses $400 each year.

Assume the value continues to decrease the same amount each year. If f(x) represents the value of the office machine after x years, which linear function models the given situation?
A ) f(x) = 400x + 3,600
B ) f(x) = -400x - 3,600
C ) f(x) = -400x + 3,600
D ) f(x) = 400x - 3,600