Answer:
D. is the correct answer.
Step-by-step explanation:
To correctly punctuate each of the lines, this is how you would need to write them (I have bolded all of the corrected/added characters):
A. "Where are you going," Mom asked, "and how long will you be gone?"
B. They said, "We haven't been outside yet."
C. "What are you doing?" she asked me.