What does “plant” mean in the sentence “the plant provides forty percent of the country's electricity”?

A. a factory or building where an industrial process happens.
B. a living thing that grows in the earth and has a stem, leaves, and roots.
C. something illegal or stolen that is hidden in someone’s clothes or possessions to make them seem guilty of a crime.
D. someone who is put somewhere or sent somewhere secretly to find out information .