怪题请教

Q41:

Gas hydrates, chemical compounds of water and natural gas, are increasingly being studied for their potential to be huge reservoirs of energy, possibly causing sea floor instability, and significant contributors to global warming.

1. to be huge reservoirs of energy, possibly causing sea floor instability, and
2. to be huge reservoirs of energy, possibly causing sea floor instability, and even as
3. as huge reservoirs of energy, possibly causing sea floor instability, and
4. as huge reservoirs of energy, and the possible cause of sea floor instability,
5. as huge reservoirs of energy, as possible causes of sea floor instability, and even as

the answer is A, I chose E

Apparently E is better,  don't u think so?

Thanks for your help!

The meaning of choice E is distorted by changing "possibly causing", which modifies "energy" in the original sentence, to a parallel noun phase structure "possible causes", which becomes one of the potential reasons.