According to the passage, which of the following is one of the first things to occur when

According to the passage, which of the following is one of the first things to occur when cells are injured？

A．The flow of electrical impulses through nerve cells at the site of the injury is broken.

B．The production of substance P traveling through nerve cells to the brain increases.

C．Endorphins begin to speed up the response of nerve cells at the site of the injury.

D．A flood of prostaglandins sensitizes nerve endings at the site of the injury.

E．Nerve cells connected to the spinal cord become electrically quiescent.

请帮忙给出正确答案和分析，谢谢！