As more and more people invest their money in savings certificates or

OFFICIAL EXPLANATION
• A, the best choice, most precisely establishes that the action of the main clause is a consequence
of the action of the introductory clause, and that the two actions are continuing contemporaneously.

• While in B and E is less clear than as because while can indicate contrast or concession
rather than contemporaneity.

• The present perfect tense in these choices is also inappropriate; contemporaneous actions should be expressed
by verbs of the same tense.

• C contains an awkward use of the passive.

• B, C, D, and E alter the original meaning by changing more and more from an adjectival to an awkwardly placed
adverbial phrase: that is, more and more no longer modifies people but loosely describes
the action of investing money in savings certificates.

That official explanation is thorough and good.

Prateekj05 posted the clearest and best answer. Kudos!