Both PL/I, which had been adopted by Multics, and BCPL/B were very familiar. PL/I , even gutted as it had been for Multics, was much too big to contemplate. BCPL's integration of subscripting and pointers was nice, as was its closeness to the machine. Typlessness was a drawback: how would one integrate floating point or characters? Another was the global vector, like Fortran COMMON. 

Algol W was known (to me, at least) only via its publication in CACM. I don't recall it having been considered. Because Algol W had more concepts than BCPL,was not as closely matched to machine-level coding, and (I believe) was equally lacking in separate-compilation facilities, I suspect it would not have made the cut.

Doug