若N_A表示阿伏加德罗常数的值，下列有关叙述不正确的是（　　）

A．常温下，28g乙烯与已烯混合物中所含共价键数目为6N_A

B．1molNaHSO₄熔化后阴阳离子数之和为3N_A

C．2.0gD₂O的中子数为N_A

D．标况下22.4LNO与33.6LO₂混合后气体分子数小于2.5N_A电解

—Are there any balls under the chair?

—______.[ ]

A. Yes, there is

B. Yes, they are

C. Yes, there are