题目8单选题
某企业在短期内的总成本函数为 <img src="https://tihai-oss-cloud.itihey.com/img/b8863edf178bbf1c718a9e4f51b33fc2.png">,那么其边际成本(MC)函数为A. <img src="https://tihai-oss-cloud.itihey.com/img/6f14165f816f0e19ef51e7c3c8500840.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/a92d230a1f9f565b2616bcd8586ed5f8.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/310f86942f79464bce7d26fc34b40ae3.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/d48fec8fff4f15b523de1c2922212ad2.png">