Please look at the following
Undoubtedly these are shocking details. But legal cases, allegations and political slugfests are unable to capture the experience of the spectator. It is he who has to endure the consequences of the mess that has erupted inside the association.
Here in the above highlighted part, the spectator in question is singular, which of the following two would be correct to use
a) It is they who has to endure the consequences.
b) It is they who have to endure the consequences.
Which one is correct of the two?