When refering to number of people, which is a discrete countable, we should use few and not less.

So eliminate A.

In C, which incorrectly modifies movies to imply that movies is less than those killed

In D, how can a number be lower than people themselves? A number can only be lower than another number.

In E, "ones" cannot be used in such a parallel conctruction unless the other part contains "people killed by the great white shark".

E is a tricky choice. We can only use parrallel construction with those/ones/that if we have exact parallelism in the other part of the sentence. "the ones killed by bee stings" could have been correct if we had "people killed by the great white shark".

The important thing to note here is that there should be nothing else between people and killed since there is nothing betweem "the ones" and "killed". However we do have "this century have been" i between "people" and "killed". Hence this construction with "the ones" is wrong. The same rule holds for "those" and "that". This is another reason why A and C are wrong

PS: Some key points regarding few vs less on GMAT

We use "less" when referring to non countables or to show continuous measurement.

"Few" is used for discrete countables.

E.g. Less money (uncountable), less than 3.5 kms (continuous measurement).

However, there is one contradiction. In case of continuous measurement if we do not use "than" and directly have noun followed we use "fewer". E.g. Sapana ran fewer kms today morning than she did yesterday.

We should also use "less" when we are referring to collective amount of something, as this is treated as uncountable. e.g. the length of the essay is less than 600 words.

Use "few" if you refer to discrete countables, as in individual units. E.g. Do not write fewer than 20 words on this topic.