My answer is
(D). It took me 01:06. Focus on parallelism.
(A) Clearly "to provide" is not parallel with "extending" or "offering".
An alternative analysis is that "extending" and "offering" are parallel, working together to modify the previous clause. But, in this case,
1. The comma before "and offering" must be eliminated.
2. A comma should be added after "retirement benefits".
3. It also conveys nonsensical meaning that, as the result of proving wider health insurance coverage, paid vacation time is thus extended, and better retirement benefits are also offered.
(B) While we can grudgingly accept the parallelism between "wider health insurance coverage", "extension of paid vacation time" and "offer of better retirement benefits", this construction is rather awkward. In particular, using verb (such as extend) is better than its noun counterpart. Keep for now.
(C) "Find it necessary to..." is how we use "it" to stand in for the infinitive. Rarely do we use gerund this way.
(D) An instant winner. Compare (D) with (B) to appreciate this much improved version.
(E) See (B).