The particular design of muscles and bones in the neck and limbs of the turtle allow
that it can draw in its exposed parts such that an attacker can find nothing
but hard shell to bite.
A. allow that it can draw in its exposed parts such that
B. allow it to draw in its exposed parts, and so
C. allows for it to draw in its exposed parts and that
D. allows that it can draw in its exposed parts, and so
E. allows it to draw in its exposed parts, so that

i think the answer should be e but it is given as d

kindly help