plz help!!

Suppose the linear cost function C(x) = 6x gives the cost for buying x items. If the items are sold in packages of 10, and no one can buy more than 5 packages, then the RANGE of the function C is

A[0, 50]

B[5, 10]

C{0, 6, 12, 18, 24, 30}

D{0, 60, 120, 180, 240, 300}