下列各组中，属于同位素的是（    ）

A．H₂、D₂、T₂

B．金刚石和足球烯C₆₀

C．¹⁶O和¹⁸O

D．H₂O和D₂O

Kate doesn't watch TV _____ weekdays. She watches TV only _____ Sunday evening. [ ]

A. in; on

B. on; on

C. in; /

D. on; in