Answer D is not correct, as gymnosprems are used widely for consumer goods such as lumber, soap, and nail polish.
Answer C is not correct event though wheat and corn are two of the main foods supplied to people in the world.
Answer B is a very subjective question, because some people argue that selective breeding helps agriculture, while others do not.
The correct answer is A. The green revolution was a period of scientific discoveries that lead to an increase in the supply of food worldwide.
