Question

osteichthyes is a group of fish that have the derived characteristics of jaws and true bones. which letter corresponds to where osteichthyes belongs on the cladogram?
a
b
c
d

Explanation:

Cladograms group organisms by shared derived traits. The first blue mark shows the origin of jaws, so A, B share jaws. The second blue mark is a unique derived trait for A, which matches Osteichthyes' additional trait of true bones (beyond jaws). B lacks this second trait, C/D lack jaws entirely.

Answer:

A. A