Nobody could given the correct answer,______?就是反义疑问句.

Nobody could given the correct answer,______?就是反义疑问句.
Nobody could given the correct answer,______?就是反义疑问句.

Nobody could given the correct answer,______?就是反义疑问句.
could they
当陈述部分的主语是everyone,no one,nobody 等时,后面的疑问句应表示为：
Everyone is in the classroom, aren't they?
Nobody will go, will they?

can he?

could they