Hi

Question from GMATPrep:

Only seven people this century have been killed by the great white shark, the man-eater of the movies-less than those killed by bee stings.
A. movies-less than those
B. movies-fewer than have been
C. movies, which is less than those
D. movies, a number lower than the people
E. movies, fewer than the ones

Official answer: B

I have looked through the explanation for this answer on various forums but am not still fully convinced about two things:

A) Why is option E incorrect, and
B) Explanation on various forums say that in order to maintain parallel structure we have to have 'have been killed' and cannot have 'killed' in the correct answer. My question is what is wrong in a simplified sentence below:

Seven people have been killed by sharks - fewer than those killed by bee stings.

As per my understanding, the meaning is conveyed appropriately even without 'have been'. Is there anything I am missing? This question is driving me mad and is lowering my confidence in dealing with 'Than' structures. Please help!

Also, does anybody have official GMAC explanation on this question?