The panda and bear comparision

[backha]

Though laypeople often refer to the panda as a bear, due to its physical resemblance to one, DNA testing has shown that it is more closely related to the common raccoon than any member of the bear family.

a) because of its physical resemblance to one, DNA testing has shown that it is more closely related to the common raccoon than

b) because of its physical resemblance to one, DNA testing has shown that it is more closely related to the common raccoon than to

This is from a MGMAT CAT and the explanation is unclear. Why is b correct?

Is this a parallelism thing, "more related to X than to Y.."?

thanks!

[jlucero]

(A) X is more closely related to Y than Z. (ambiguous)
(B) X is more closely related to Y than to Z.
(C) X is more closely related to Y than Z is.

Notice that adding a "to" clearly shows that Y and Z are each being compared. When you use the first comparison, you could be saying that X is more closely related to Y than Z is related to Y. (A) is pretty ambiguous either way. Either include a "to" to compare Y and Z (B), or include an "is" after the Z to compare X and Z (C).