The diagram shows a cross-section of the Earth including the location of upper (3) and lower (5) mantle, and outer (7) and inner (9) core. What is thought to be source of plumes?

A) 4
B) 5
C) 6
D) 7

The diagram shows a crosssection of the Earth including the location of upper 3 and lower 5 mantle and outer 7 and inner 9 core What is thought to be source of class=