Answer : Option A) "He belays Hillary with rope support up the mountain which reduces the risk of Hillary from falling."
Explanation : When Referring to the Explorations in Literature.
In "The Final Assault," Hillary explains how he and Tenzing Norgay climbed Mount Everest together. Norgay contributes to the success of the climb as he belays Hillary with rope support from up of the mountain which certainly reduced the risk of Hillary from falling. If this wouldn't had been done, then there were high chances of Hillary to fall.