“I’d like to give my thanks to those _____ help my son was able to survive this terrible disease,” said the woman on TV.

A．who

B．whose

C．with whose

D．with whom

为支援汶川地震灾区重建家园，某校四年级学生捐款540元，是三年级的2倍，这两个年级共捐款多少元？