Answer: This is a tricky question but I think it’s either a or c
Explanation: sorry if it’s wrong
Schist has the highest metamorphic grade.
Mansa was a royal title for leaders of the Malian Empire. It means something like "King" or "Super-King" or "Kingiest King."
Mansa Musa was one of the most important Mansas. He lived from the late 1200s to the early 1300s, and reigned over the Malian Empire at the peak of its power.
The change of heat among oceans could no longer occur.