Quite sure C is correct ;) remember that humans are also placental mammals.
A situation where friction would be desirable is rubbing your hands together to make them warm in the winter time.
If Jerry wants to start a small business producing jelly made from marine algae he should select red algae for this purpose. Red algae is a major staple in some Asian and European cuisines.
Angiosperms are grouped into monocots and dicots
