Puzzling elements of human anatomy and behavior, such as having small jaws, the late eruption of teeth, and a tendency for playfulness, can be explained with the term neoteny, which is the retention of features of the immature specimen in the adult of the same species.
A.
having small jaws, the late eruption of teeth, and a tendency for playfulness, can be explained with the term neoteny, which is the retention - parallelism error, also the term refers to something and not the term itself is something
B. small jaws, the late eruption of teeth, and a tendency for playfulness, can be explained with the term neoteny, which refers to the retention - correct
C. small jaws, the late eruption of teeth, and a tendency to be playful, explained with the term neoteny, which refers to the retention - playful is adjective whereas jaws and teeth are noun- wrong parallelism, also can be explained "verb" is missing.
D. tending to be playful and having small jaws and teeth that erupt late, can be explained with the term neoteny, which means to retain- wrong parallelism
E. small jaws, late-erupting teeth, and a tendency for playfulness, can be explained with the term neoteny, which means the retaining- "the retaining of features" noun is not preferred, the retention of features is preferred construction.
Hence the correct answer is B.