Answer:
C. Be satisfied because he is already maximizing his total utility
Step-by-step explanation:
As the amount of utility provided by the 10th magazine is the same as the 25th newspapper we can determinate that Frank is in a maximizing point of their utility curve. That's because replacing Magazine for newspapers will make a difference between each other marginal utility and thus, being preferable to pick one over the other. Currently Frank utility is the same for both product so there is not desire to replace one from another.