Creosote Inc. operates a plant—a "major source"—that emits hazardous air pollutants for which the Environmental Protection Agency has set maximum levels of emission. The plant does not use equipment to reduce its emissions. Under the Clean Air Act, this is most likely
a. a violation.
b. not a violation because a "major source" is exempt.
c. not a violation because the plant does not use any equipment.
d. not a violation because the plant is not a mobile source.