13. 由齒狀回 (dentate gyrus) 投射到海馬回 (hippocampus) CA3 區的纖維是:(A) 穹窿 (fornix)(B) 雪佛側枝 (Schaffer collateral)(C) 苔纖維 (mossy fiber)(D) 穿通纖維 (perforant fiber)