Answer :
Final answer:
According to William Sheldon's somatotype theory, Rachel would be classified as an ectomorph, which describes individuals who are naturally very thin and have a hard time gaining weight.
Explanation:
William Sheldon, who was a psychologist, developed a body classification system. According to Sheldon's somatotype theory, there are three basic body types: ectomorph, endomorph, and mesomorph. Given the description of Rachel as 'very thin and frail', Sheldon would most likely classify her as a ectomorph.
Ectomorphs are characterized by a slim, linear appearance and small bone structure, and often find it difficult to gain weight or muscle mass. This body type contrasts with endomorphs, who have a rounder and softer physique and tend to store more body fat, and mesomorphs, who have a more muscular and well-defined build, and easily gain muscle.
