__ reflection,he decided to go abroad for further study.

问题描述:

__ reflection,he decided to go abroad for further study.
A、Through B、 After C、 On D、 By
为什么选C?请翻译整句

on reflection是个词组,意思是经过考虑.
整句的意思是:经过考虑,他决定出国进一步学习.