Hi phanikpk,

This SC is based on a couple of standard grammar rules:

1) Parallelism - The sentence tells us 2 things that the new jet engine might be able to do. We have to make sure that the two things are written in "parallel format", meaning that the phrases include the same "types" of words and are written in the same "order." The verbs are easy to focus on, so let's consider the options. Both verb phrases need to either both be infinitive verbs OR both be "-ing" verbs (so either "propel....and help...." or "propelling....and helping...." would be correct). Eliminate B, C and D.

2) Style/Redundancy - Between answers A and E, answer E includes a number of unnecessary/redundant words ("and it....have the capability"). Eliminate E.

Final Answer: A

GMAT assassins aren't born, they're made,
Rich