___ the help of their group,we would not have succeeded in te investigation.

问题描述:

___ the help of their group,we would not have succeeded in te investigation.
A、Besides B、 regardless of C、 But for D、 Despite
为什么选C?请翻译整句?

but for要不是
要不是他们那组的帮助,我们在研究中就不会成功.