The airport custodial staff, which (A) hasn't been working under contract for a year, (B) are thinking about (C) striking if management (D) doesn't agree to salary increases.
I think (B) should be corrected to is thinking because in American English "staff" is considered a singular noun.
But, what I would like to ask is about the relative pronoun "which". Do you think if using "who" is much better? Please advise.
LCChang