Like other forms of physical activity, tai chi might help mitigate the

OFFICIAL EXPLANATION


• HIGHLIGHTS

• This question tests parallelism
The sentence presents two effects of practicing tai chi: X goes up, Y goes down.
When two items are presented this way, you can assume that
(1) the question tests parallel structure, and
(2) the correct answer will list the items on either side of the construction in the same format

• This question also tests the idiom Such X as Y.
-- You can eliminate two answers on the basis of a botched idiom, Such X as Y
More information about "such as" and "such X as Y" is below.

• I use questions such as this one to teach about concepts tested even when those concepts aren't the most important issues. (There is method to this madness. Stay tuned.)

I have changed the order of presentation in this post.
My "Notes" are just below "Comments."

THE PROMPT

THE OPTIONS
• the effects of tai chi are not written in parallel form.
-- reducing ___ is a verb-like noun phrase (a "gerund phrase, no verb) whereas levels . . . are increased is a full clause (a noun plus a verb)
Eliminate A

• although the items in option B may seem to be parallel, they are not
• true, reduction and levels are both nouns.
• but reduction of levels of ___ is a noun phrase (without a verb) whereas levels of ___ increase is a full clause (with a verb)
Eliminate B
• the idiom is Such X as Y, not Such X like Y
Although the words "such as" are split apart, still, we use such as to introduce examples, not such like.
• the items are not parallel; the problem is similar to that in option A.
-- the reducing of ___ is a gerund phrase (no verb) whereas levels of ___ are increasing is a full clause (noun + verb)
Eliminate C

• the items are not parallel
-- harmful triglyceride levels are reduced is a full clause (with a verb) whereas increasing "good" HDL cholesterol levels is a gerund phrase (a verbING phrase, no verb)
• the sentence is nonsensical
-- Its effects are such that increasing "good" HDL cholesterol levels. A verb is missing.
• such that is almost never correct—in any context.
-- Almost never = I can't find one single correct answer that uses "such that."
-- See below. I discuss official examples that have tested "such that."
Eliminate D
• the items are parallel and logically related.
-- a reduction in [bad cholesterol] and an increase in [good cholesterol] are both noun phrases
-- the logic is clean: ABC decreases and DEF increases

Option E is the answer

COMMENTS

I am happy to see posts from people I have not seen for awhile.
As always, I am happy to see posts from consistent participants.

Explanations range from good to excellent. Kudos to all.


• NOTES

Such X as Y [and Z]

Correct: Such X as Y and Z.
Correct: He enjoys playing such racket sports as tennis and squash.
Wrong: Such X like Y and Z
Wrong: He enjoys playing such racket sports like tennis and squash.

An official question in which the idiom is tested can be found here.
Spoiler alert: that question is both good and difficult.
If you click on the link armed with what I just wrote, you will almost certainly know the answer.

SUCH THAT: avoid it in any context.

In another question (a very good one), I included the information immediately below.
I doubt that my considerable effort was worth it. It appears that aspirants neither noticed nor cared.
I would care. I'll try one more time, because "such that" is a fairly common issue.

SUCH THAT
I cannot find ANY official questions in which the phrase "such that" is correct.
I've listed six of the eight or nine official questions I found in which "such that" was part of an answer choice.

SPOILER ALERT: If you click on these links to official questions, you will know at least one incorrect answer.
OFFICIAL QUESTIONS in which such that is an option but not the correct answer.
HERE, #1
HERE, #2
HERE, #3
HERE, #4
HERE, #5
HERE, #6

LIKE v. SUCH AS distinction? Still true?

First, "such like" is never correct, whether the phrase is in one piece or split apart.

Second, if at all possible, I would follow the guideline that we use such as to introduce examples.
We do not use like to do so. Like is used for comparisons.

Some controversy exists about whether GMAC has abandoned the distinction between such as and like.

This issue is not easily settled.
At least one official question uses "like" in the non-underlined portion of the question.
That question is here.
We don't have a choice. The word "like" introduces examples.
[Sidebar. In CR and RC, I have seen "like" used to introduce examples.
Do not rely on prose in CR, RC, or the official guides as an example of GMAC's position on an SC issue.]

Many people believe that GMAC will abandon this preference soon.
Before I saw OG VR 2020, I might have agreed.
I thought that one question would disappear from OG VR 2020.
The question explicitly tests such as and like to introduce examples, although both incorrect options that use like have an additional error.
The question did not disappear from OG VR 2020.

Its official explanation states:
The preferred way to introduce examples is with the phrase "such as," rather than with the word "like," which suggests a comparison.

Spoiler alert: two incorrect answers to an official question are revealed

At this point I would not use such as/like as the only basis upon which to eliminate an answer, but if you narrow the answers down to two, choose the one that uses "such as."