gmat prep sc.. scaly tailed squirrels..

[kshitijg17]

The parachutelike membranes of Africa's scaly-tailed flying squirrels differ from those of the flying squirrels in the family Sciuridae --because they are attached to a cartilage rod at the elbow instead of-- the wrist.
(A) because they are attached to a cartilage rod at the elbow instead of
(B) because of being attached to a cartilage rod at the elbow rather than at
(C) in their attachment to a cartilage rod at the elbow instead of being attached at
(D) in that they are attached to a cartilage rod at the elbow rather than at
(E) in their being attached to a cartilage rod at the elbow instead of

OA is D
why is B incorrect?

can someone pls clarify when to use instead of and when to use rather than?

[RonPurewal]

please search the forum. thank you.

https://www.manhattanprep.com/gmat/foru ... t1980.html