Y quienes _____?

Complete with ser.

THNX!!!

3 answers

There's insufficient information to determine this verb form.
well okay i found the answer so thanks anyway
Do not forget punctuation marks, in spanish we use open and close mark.
Ms. Sue is right, there is not sufficient information but there are only three possibilities (without auxiliary verb)
a.- Fueron
b.- son
c.- serĂ­an
/three differents tenses, in the three options we use plural