Can you explain ______ the OPEC can have such total control over the price of oil?

A．how is it that

B．that how

C．how it is that

D．what is it

甲县执法部门因商户A未缴纳罚款查封了A的一批鲜奶，依法变卖后发现A实际已补缴罚款，该批鲜奶不再需要查封，（）

A.应当返还拍卖或者变卖所得的全部价款

B.无须对当事人给予补偿

C.可以对当事人给予补偿

D.因违反规定变卖或者未及时变卖造成当事人财产损失的，当事人有权要求赔偿或者补偿