Answer: a) Personal experience
Step-by-step explanation:
Personal experience is defined as the experience that is gained from the moment to moment situation that person undergoes in his/her life.These events act as experience through which awareness regarding internal and external factors is established in life period.
According to the question, the person is suspicious about Rose's behavior because of personal experience he has gained through past event where students tried to be nice with him so that he will help them in studies.
Other options are incorrect because relationship closeness with Rose and knowledge about Rose are not the factors that describe moment to moment experience of the person that creates awareness in him/her about events..
Thus, the correct option are option(a).