The Orangutans Found in Borneo Tend to Lead a Solitary

The orangutans found in Borneo tend to lead a solitary existence because they have to forage far and wide for sufficient food.In contrast,fruits and insects are sufficiently abundant in the swamps of Sumatra to sustain groups of adult orangs and permit coordinated group travel.Thus,we can say that:

A) orangutans in Sumatra tend to be heavier because they don't have to search so hard for food.
B) a solitary existence is a function of habitat productivity.
C) habitat productivity promotes harmony.
D) gregariousness is a function of habitat productivity.
E) coordinated group travel is a function of lack of habitat productivity.