问题详情

Why are boys more at risk, especially the overweight boys？

A．Boys like vigorous sports, so their heart bear more burden.

B．Boys don"t like go to hospital to receive ultrasound treatment.

C．Their hearts are usually too big to pump blood very well.

D．Their hearts are over worked to support their bodies if they are overweight.

请帮忙给出正确答案和分析，谢谢！