Questions 10-11 are based on the following passage. According to the theory of plate tectonics, the lithosphere (earth’s relatively hard and solid outer layer consisting of the crust andLine part of the underlying mantle) is divided (5) into a few dozen plates that vary in size and shape; in general, these plates move in rela- tion to one another. They move away from one another at a mid-ocean ridge, a long chain of sub-oceanic mountains that forms a (10) boundary between plates. At a mid-ocean ridge, new lithospheric material in the form of hot magma pushes up from the earth’s interior. The injection of this new lithos- pheric material from below causes the phe- (15) nomenon known as sea-floor spreading. Given that the earth is not expanding in size to any appreciable degree, how can "new" lithosphere be created at a mid-ocean ridge For new lithosphere to come into (20) being in one region, an equal amount of lithospheric material must be destroyed somewhere else. This destruction takes place at a boundary between plates called a sub- duction zone. At a subduction zone, one (25) plate is pushed down under another into the red-hot mantle, where over a span of mil- lions of years it is absorbed into the mantle. It can be inferred from the passage that as new lithospheric material is injected from below

A. the plates become immobilized in a kind of gridlock
B. it is incorporated into an underwater mountain ridge
C. the earth’s total mass is altered
D. it reverses its magnetic polarity
E. the immediately adjacent plates sink