Adam is a member of a research group at a university. One of his tasks as a group member is to present the group's research progress before the university's faculty every month. Even though the dates of the presentations are announced in advance, Adam is never prepared with the complete presentation. As a result, he is often unable to answer questions from the audience. Based on this information, it can be said that Adam most likely plays the role of a$($n$)\_\_\_\_\_$ in his research group.

Group of answer choices

detractor

aggressor

airhead

isolator