Choose the option in which the prepositions complete the verb phrases, respectively:
1. The problem stems __________ the government’s lack of action.
2. When I asked Jean, she hinted ________ the chance of a promotion for me.
3. The salesman was responsible ________ the accident.
4. Please, refrain _________smoking in the lecture lounge.
5. I can’t stand the way she is always boasting _______ her wealthy parents.