In that form, the singular factor matches with the verb causes. What causes coral bleaching ? If you simply want to say the person or thing that makes something happen, you say 'cause of';
Update Calgary storm upends trees, causes traffic delays across city
But if you want to say a reason for. In both situations there is a lack of resources which causes people to die. Is this the only factor that causes such tragedies?
What does cause coral bleaching ?
There's a lack of some. This sentence should be read as follows: In the grammar test below, why option 3 is not correct?
