Read the paragraph.
While walking to school, Steve and Matt saw four puppies on the sidewalk. One of them had dark blue eyes. The puppy with the brown spots was very playful. It kept running after Steve. The black puppy was so scared that it hid behind a fire hydrant. Steve and Matt played for a while and then they continued on their way to school.
Which underlined pronoun is vague or unclear and should be changed?
A. it
B. their
C. they
D. them