The idea that bipedalism developed so that males could provide food to their female pair and ...

The idea that bipedalism developed so that males could provide food to their female pair and offspring is considered culture bound because of all of the following reasons except:
 
  a. pair bonding is not found frequently among terrestrial primates.
  b. males of all species routinely gather excess to provision females whether or not they need it.
  c. female primates routinely forage for food while carrying offspring.
  d. early pair bonding is not evident in the genus Homo.
  e. females are not usually highly restricted because of the dependence of offspring.