Is important to cancer patients because it is a two-way fight:
A Immune system
B Antibodies
C Antigen system
D none of the above

I believe the answer is A. Immune system and B. antibodies.

Explanation:

I think this is it because cancer is caused by multiplying cells in the Immune system, and the body is at war with itself, so that's why I believe this is the answer. Also because the antigen system is blood types, and that seems kinds irrelevant to the question. Hope this helps!

well say a good goal is to do 150 sit ups in a week! or 90 pull ups a day. even 60 push ups in a month these are all fair goals!