问题详情

The scientists at the Kennedy Space center laboratory have been able to produce small kinds of ______.
A．wheat, soybeans, carrot and lettuce
B．soybeans, tomatoes, carrot and wheat
C．white potatoes, carrot, lettuce and soybeans
D．wheat, soybeans, lettuce and white potatoes请帮忙给出正确答案和分析，谢谢！