Which does not belong to the scientific breakthroughs in the 21st century？

Which does not belong to the scientific breakthroughs in the 21st century？ 查看材料

A.We"ll know whom we are.

B.We"ll live longer.

C.We"ll conquer cancer.

D.We"ll manage Earth.

请帮忙给出正确答案和分析，谢谢！