Answer:
The correct answer is (B) An interpersonal utility comparison
Step-by-step explanation:
Solution
Interpersonal utility comparison: refers to the summation of utility functions of different persons determined on the utility functions being comparable with each other; informally, individuals' choices must be evaluated with the same standard.
The ability to produce a social welfare function depends decisively on the ability to contrast utility functions.
In this case your roommate made an Interpersonal utility comparison.