Basil is maximizing his utility from consuming tea and crumpets. If the marginal utility of the last crumpet was 32 units of utility and the prices of tea and crumpets are 4 and 8, respectively, what was the marginal utility of the last cup of tea Basil consumed?
a. 2 units of utility
b. 12 units of utility
c. 6
d. 128 units of utility
e. 16 units of utility