题目3单选题
已知<img src="https://tihai-oss-cloud.itihey.com/img/0d7a1ba7daa55d892a9efa6fa4186cae.gif">,则<img src="https://tihai-oss-cloud.itihey.com/img/12fb8911d717670a807882e4edbe92bc.gif">中<img src="https://tihai-oss-cloud.itihey.com/img/a8d382651e65022090121c234a9e2388.gif">,<img src="https://tihai-oss-cloud.itihey.com/img/e3cf05e980523c22ef0aa60968a8fe0e.gif">的系数分别是A. 2,-1B. 2,1C. -2,1D. -2,-1