What is the process which scientists grade the work of other scientist before published?

The process is called Peer-Reviewing. In Peer-Reviewing, scientists/academic peers "peer review" the work of a scientist to check for accuracy or any false information that might reduce the legitimacy of their study or change "how realistic/real" their study is.

p.s. This is also common sense because scientists make up an entire scientific community who base their scientific studies on consistency and accuracy. 

The correct answer is d. Antarctica must have been in a different warmer location in the past. The presence of Glossopteris in Antarctia proves that the continent was located closer to the equator and have since drifted to the south pole. This observation supports the theory of continental drift.