Human being, because a human being walks on all fours in early life, on two legs as an adult and with a walking stick in old age.
I hope this helps you.
The adjective phrase is... with red polka dots. It describes the ball.
Smilie - "like a feather"
I believe that the answer is C - remind readers of the relevance of the topic. From what I have learned you don't directly restate your thesis, you summarize your main points.
