Question

Recent studies have shown that babies do have unique cries to identify their needs, and
interpreting a baby's vocalizations is not as difficult as it may seem.
A. needs. Interpreting
B. needs; interpreting
C. needs, so interpreting
D. needs, interpreting

Answer 1

I would say the answer is D

Answer 2

The answer is A. These sentences are 2 different sentences and need to be separated to avoid creating a run-on.