If Joan Consumes 1 Dinner Roll,she Has Total Utility of 15;

Multiple Choice

If Joan consumes 1 dinner roll,she has total utility of 15; if she consumes 2,she has total utility of 27; if she consumes 3,she has total utility of 37; and if she consumes 4,she has total utility of 45.What is the marginal utility of the fourth dinner roll consumed?

A) 124 units of utility
B) 45 units of utility
C) 11.25 units of utility
D) 8 units of utility
E) 37 units of utility