麻烦大家帮忙解答一道英语选择题

题目

麻烦大家帮忙解答一道英语选择题
I jumped into the water to cut off the sound and (mechanically) began my stroke.
A、emotionlessly
B、energetically
C、swiftly
D、confidently
（用选项代替括号里的单词）

答案

A
括号里单词为“机械的”
A 面无表情的,冷漠的 B 有活力地 C快速的D自信的