The following sentence is from a formal conversation. The student is talking to a teacher.
実は日本語のクラスでプロジェクトワークをしていまして、私は日本の歴史の教科書をトピックに選びました。
Can someone explain to me the exact meaning of "教科書をトピックに選びました"? Literally translated it appears that he "chose a textbook", but that seems like a strange thing to say, since students don't normally choose their own textbooks (no other context about the project work is given). As an adverb, I'm not sure what トピックに could mean.
Alternately, could it be an equivalent of 教科書をトピックにする, i.e. "make the textbook into the topic" of the project? Is it common to replace にする with other verbs such as に選ぶ, if this is the case?