A teacher has a 2- gallon (32-cup) container juice. she gives each student 1/2 cup of juice. Which equation represents the amount of juice that remains, y, after x students are served?
A. y = 32x - 1/2
B. y = 1/2x - 32
C. y = -1/2x + 32
D. y = -32x + 1/2