18. When and where would you expect to find the highest rate of primary productivity? O A. In the polar regions during the summer months
O B. In the tropics during the fall
O C. In the temperate regions during the summer months
O D. In the polar regions during the fall

b would be the right answer

a

explanation:

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.