If a red-tailed squirrel population grows too large and leads to a strain on habitable space, a female red-tailed squirrel will sometimes allow their daughters to settle nearby, with about half accepting the invitation.
A. large and leads to a strain on habitable space,
a female red-tailed squirrel will sometimes allow
their daughters to settle nearby, with about half accepting...................'Their' refers to the singular female red-tailed squirrel.
B. large,
this leads to a strain on habitable space, a female red-tailed squirrel will sometimes allow her daughters to settle nearby, with about half accepting...............use of 'this' changes the intended meaning.
C. large, leading to a strain on habitable space,
a female red-tailed squirrel will sometimes allow
their daughters to settle nearby, with about half accepting............Same as option A
D. large, leading to a strain on habitable space,
a female red-tailed squirrel will sometimes allow
her daughters to settle nearby, and about half will accept...............looks fine.
E. large,
which leads to a strain on habitable space, a female red-tailed squirrel will sometimes allow her daughters to settle nearby, and about half will accept.....................'which' wrongly modifies large/grows.
OA D.