As criminal activity on the Internet becomes more and more sophisticated, not only are thieves able to divert cash from company bank accounts, they can also pilfer valuable information such as business development strategies, new product specifications, and contract bidding plans, and sell the data to competitors.


(A) they can also pilfer valuable information such as business development strategies, new product specifications, and contract bidding plans, and sell

(B) they can also pilfer valuable information that includes business development strategies, new product specifications, and contract bidding plans, and selling

(C) also pilfering valuable information including business development strategies, new product specifications, and contract bidding plans, selling

(D) but also pilfer valuable information such as business development strategies, new product specifications, and contract bidding plans to sell

(E) but also pilfering valuable information such as business development strategies, new product specifications, and contract bidding plans and selling



Query- As "not only" and "but also" form a pair, why is D incorrect?



The sentence is correct as it is. The correct answer is option A. 



Option D uses the correlative conjunctions "not only" and "but also" but contains an error of parallelism.

Not only X but also Y is the structure that we have to maintain. 
In the sentence given, 
not only are thieves able to divert cash ( subject + verb) should be similar to what follows "but also". 
But in Option D, it says, but also pilfer valuable information (no subject, only verb). 
 This breaks parallelism and is hence incorrect.