In 1984 medical researchers at Harvard and Stanford universities concluded that sedentary life-styles lead to heart and lung diseases that shorten lives, strongly recommending middle-aged people to undertake some form of regular exercise.

(A). strongly recommending middle-aged people to
(B). strongly recommending that middle-aged people should
(C). and strongly recommended for middle-aged people to
(D). and their strong recommendation was for middle-aged people to
(E). and they strongly recommended that middle-aged people

GMATGuruNY wrote:

In 1984 medical researchers at Harvard and Stanford universities concluded that sedentary life-styles lead to heart and lung diseases that shorten lives, strongly recommending middle-aged people to undertake some form of regular exercise.

(A). strongly recommending middle-aged people to
(B). strongly recommending that middle-aged people should
(C). and strongly recommended for middle-aged people to
(D). and their strong recommendation was for middle-aged people to
(E). and they strongly recommended that middle-aged people

A bossy word serves to express a command or recommendation: suggests, recommends, insists, etc.
Bossy words typically require the COMMAND SUBJUNCTIVE.
The structure of the command subjunctive is BOSSY WORD + THAT + NOUN + BARE INFINITIVE.
The bare infinitive is the infinitive form of a verb with the to omitted.
Example: The bill MANDATES that a bank DISCLOSE its assets.
Here, mandates is a bossy word, while disclose is the bare infinitive form of TO disclose.

In the SC above, the researchers are being bossy: they are RECOMMENDING.
Only E correctly employs the command subjunctive:
They strongly RECOMMENDED that middle-aged people UNDERTAKE some form of exercise.
Here, recommended is a bossy word, while undertake is the bare infinitive form of TO undertake.

The correct answer is E.

ceilidh.erickson wrote:

aflaam wrote: Isn't they in E redundant?

Nope.

What you're suggesting is that without a "they," then the basic structure of the sentence would be "researchers concluded and recommended." This would be perfectly correct... except that there should not be a comma separating parallel verbs. We don't say "researchers concluded, and recommended."

Because there is a comma after "lives," separating the two verbs, this sentence should contain two independent clauses, rather than a subject + two verbs. So, the basic structure of this sentence is "researchers concluded, and they recommended." Perfectly correct.