5

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 

请问为什么选D不选E啊??? 不是更简洁吗,而且 and so看上去好奇怪啊...

allows it can和allows it to do sth是不同的概念

而且 so that 用在这里不合适