The correct answer is B) the windward monitor should be manned and the foam should be directed onto a vertical surface while standing by with a charged hose to protect the monitor operator with water fog if needed. This is the correct approach because in a Class B fire on the weather deck of a moored tank vessel, the fire party should apply foam from the windward side to avoid spreading the fire. Directing the foam onto a vertical surface helps the foam cling and smother the fire. Having a charged hose ready to protect the monitor operator with water fog is important for their safety. The other options are incorrect as they either direct the foam from the leeward side or do not provide water fog protection for the monitor operator.