I would have paid a visit to you _______ possible.

A．if it were

B．would it be

C．had it been

D．should it have been

患者，男，22岁，3个月前因外伤致一上前牙脱落，今要求烤瓷修复。口腔检查：左上侧切牙缺失，间隙正常，牙槽嵴无明显吸收。左上中切牙牙冠1／2缺损，已露髓，探稍敏感，叩诊阴性，无松动。左上尖牙牙冠良好，叩诊阴性，无松动。余牙未见异常。最适合的治疗方案是（）。

A.桩冠局部义齿

B.覆盖义齿

C.桩核与双端固定桥

D.根内固位体固定桥

E.以上都不是