Electron Transport Within NADH-Q Reductase, Cytochrome Reductase, and Cytochrome Oxidase

Electron transport within NADH-Q reductase, cytochrome reductase, and cytochrome oxidase can be coupled to proton transport from the mitochondrial matrix to the space between the inner and outer mitochondrial membranes, because those protein complexes are

A) in the mitochondrial matrix.
B) within the inner mitochondrial membrane.
C) in the space between the inner and outer mitochondrial membranes.
D) in the cytoplasm.
E) loosely attached to the inner mitochondrial membrane.