完全垄断厂商达于长期均衡的条件是:A.MR=MCB.MR=SMC=LMCC.MR=SMC=LMC=SACD.MR=SMC=SAC=LAC

完全垄断厂商达于长期均衡的条件是：

A.MR=MC

B.MR=SMC=LMC

C.MR=SMC=LMC=SAC

D.MR=SMC=SAC=LAC

请帮忙给出正确答案和分析，谢谢！