Richard was asked to withdraw from graduate school because ........ .
1. they believed he was not really able to complete research
2. he was deemed incapable of completing his research
3. it was decided that he was capable to complete the research
4. his ability to finish the research was not believed or trusted
I know that #2 can fit here. However, I don't know why we should not choose #4 instead. ( If my question is appalling, don't answer it. I do not want to take up your time. Leave it without any answer!)