Refer to the Figure

Multiple Choice

Refer to the figure.In an experiment to test the function of leptin in mice, parabiotic twins were created by surgically connecting the circulatory systems of a wild-type (WT) mouse with an obese mouse or a wild-type mouse.The obese mouse either lacked functional leptin (genotype ob/ob) or lacked the receptor for leptin (genotype db/db) .After allowing the mice to feed at will, they observed the results shown in the figure. It is most likely that

A) mouse 1 has a genotype of ob/ob.
B) mouse 1 is a wild-type mouse.
C) mouse 2 has a genotype of db/db.
D) mouse 2 could be wild-type or have a genotype of ob/ob.
E) mouse 3 has a genotype of db/db.