It can be seen from the passage that the problem of resource conservation in agriculture _

It can be seen from the passage that the problem of resource conservation in agriculture ______.

A．has been solved in the U.S.

B．has not yet been paid any attention to

C．is being seriously and effectively dealt with

D．will soon be solved by using more capital and land

请帮忙给出正确答案和分析，谢谢！