Which of the sentences below best expresses the essential information in the highlighted s

entence in the passage？ Incorrect choices change the meaning in important ways or leave out essential information.

A．More people take up mountain climbing due to publicity and better equipment.

B．There are increasing cases of both success and tragedy in mountain climbing.

C．The activity of mountain climbing has becoming less and less popular.

D．Improvements in climbing equipment are the key reason for increased popularity of mountain climbing.