Bipedalism Freed the Hands, Which Allowed Tools to Be Carried

Bipedalism freed the hands, which allowed tools to be carried. This was an advantage because

A) it built up the primates' arms for more strength.
B) it caused a preoccupation with tools so the primate did not have to worry about anything else.
C) the tools could be used as weapons against predators, if necessary.
D) there was no real advantage, as it made it harder to run from danger.