Some Bacteria Release Electrons, Which Can Then Be Bound to an Electrode

Some bacteria release electrons, which can then be bound to an electrode, generating electricity. This process may be used:

A) to produce cellulosic ethanol.
B) to produce biodegradable plastics.
C) to create microbial fuel cells.
D) to separate valuable minerals from rock deposits.
E) as a biologically produced hydrocarbon.