(A) is right.
Salicide block supresses the low-resistance layer that reduces source-drain resistance at the surface. In ESD protection one wants the current o spread thru the bulk/depth of the drain and source, because it'll dissipate heat better, and, most important, will do this as far as possible from the thin oxide of the gate/channel interface.
In (B) the ESD current will come back to the surface as soon as the salicide is available (lowest resistance path).