请教英语定语从句选择题

题目

请教英语定语从句选择题
That is the robber_____arrest a reward was offered.
A:for whom B: for whose C:about whom D:about whose
请问这道题应选什么答案,请解释详细点,谢谢~~~

答案

B: for whose
whose=of the robber
分开两句你就清楚了
That is the robber.
a reward was offered for the arrest of the robber