[QA] The passage support which of the following conclusions about mammoths?

Question:

The passage support which of the following conclusions about mammoths?

• A.
  Humans hunted them to extinction.
• B.
   The cause of their extinction is not definitely known.
• C.
  Competition with mastodons caused them to become extinct.
• D.
  The freezing temperatures of the Ice Age destroyed their food supply.