you'd better give task to ___you think can finish it ahead of time

正确答案是A.whoever
whoever 在宾语从句中作主语,后面的you think 是插入语不是作宾语吗？为什么不用whomever：(这两题是在网上看滴）1. Give it to _____ asks for it first. Give it to him. He asks for it first.Give it to whoever asks for it first. (whoever= him+ he)2. We will hire_______ is most qualified. We will hire her. She is most qualified. We will hire whoever is most qualified. (whoever= her+ she)3. We will hire_____ you recommend.We will hire them. You recommend them.Therefore, We will hire whomever you recommend. ( whomever= them + them)要看它在后面的定语人句中的作用，如果在定语从句中作主语就用whoever