Study 1 differed from Study 2 in which of the following ways?
A.
G. fortis finches were captured during Study 1 but not during Study 2.
B.
G. fuliginosa finches were captured during Study 1 but not during Study 2.
C.
The beak depth of captured birds was measured during Study 1 but not during Study 2.
D.
The beak depth of captured birds was measured during Study 2 but not during Study 1.