正常覆盖时，上颌切牙切缘到下颌切牙唇面的距离是（）。

A.7mm以上

B.5~7mm

C.3~1.5mm

D.3mm以内

Investigator: XYZ Coins has misled its clients by promoting some coins as "extremely rare" when in fact those coins are relatively common and readily available. XYZ agent: That is ridiculous. XYZ Coins is one of the largest coin dealers in the world. We authenticate the coins we sell through a nationally recognized firm and operate a licensed coin dealership.
The XYZ agent’s reply is most vulnerable to the criticism that it

A．exaggerates the investigator’s claims in order to make them appear absurd.

B．accuses the investigator of bias but presents no evidence to support that accusation.

C．fails to establish that other coin dealers do not also authenticate the coins those dealers sell.

D．lists strengths of XYZ Coins while failing to address the investigator’s charge.

E．(E) provides no definition for the inherently vague phrase "extremely rare. "