Note that when exiting the baggage claim of Terminal C to get to the bus stop for the free intra-terminal shuttle or Q70, one must turn to the right and walk the entire length of the terminal; the stop is about as distant from the exit as possible. Also note that while the Q70 is free, the M60-SBS that also routes through the terminals is not. Finally, it's not possible to walk from C to B. OP's travel department didn't do them many favors here.