Examine the Graph Below

Examine the graph below.
Research indicates that goshawk predation is much less effective when prey species, like wood pigeons, are in large flocks. If this is true why do any small flocks exist at all?

A) They do not; small flocks are just birds transitioning from one large flock to another.
B) In large flocks newly discovered food resources must be shared while in small flocks there is more food per individual bird.
C) The natural genetic variability induces some birds to live alone.
D) Single birds are simply lost and are attempting to relocate the flock.