Which of the following italicized parts is NOT a noun clause？A．That light travels in strai

Which of the following italicized parts is NOT a noun clause？

A．That light travels in straight is known to all.

B．What matters is when we shall hold the sports meeting.

C．I thought they could have completed the project.

D．The sun heats the earth, which is very important to us.

请帮忙给出正确答案和分析，谢谢！