A nutritionist wants to study the effect of storage time (6,12, and 18 months) on the amount of vitamin C present in freeze dried fruit when stored for these lengths of time. Vitamin C is measured in milligrams per 100 milligrams of fruit. Six fruit packs were randomly assigned to each of the three storage times. The treatment, experimental unit, and response are respectively:
(a) A specific storage time, amount of vitamin C, a fruit pack
(b) A fruit back, amount of vitamin C, a specific storage time
(c) Random assignment, a fruit pack, amount of vitamin c
(d) A specific storage time, a fruit pack, amount of vitamin C
(e) A specific storage time, the nutritionist, amount of vitamin C