she was already in her late fifties when she ( )took up long-distance running

问题描述:

she was already in her late fifties when she ( )took up long-distance running
A.picked up B.made up C.put up D.took up
该题正确答案应选D,请翻译一下句子并解释原因

take up 从事
当她开始从事长跑运动时,她已经50多岁了