The Idea That Interpersonal Attraction Is Tied to Physical Attractiveness

The idea that interpersonal attraction is tied to physical attractiveness makes it appear that humans are shallow. This idea can be dismissed based on which one of the following, as presented in your textbook?

A) findings have been difficult to replicate
B) inability of psychologists to define what exactly is meant by "attractive"
C) questionable external validity
D) low internal validity