The tissues of the human body are constantly moistened by a briny solu

OFFICIAL EXPLANATION



Meaning?
A salty (briny) solution constantly moistens tissues of the human body.
The salinity of that solution is believed to be nearly the same as the salinity of the water in the prehistoric sea. Life on Earth began in the primordial sea.

We could use a few splits to approach this question.

• the same X as | the same X like

• thought
thought to be of about the same
thought of as of about the same
thought to be about the same

• from which | from where

• Split #1: SAME takes AS, not LIKE

Although I did not give this detail away in my answers to people prior to posting this OE, we can focus on one word in the comparative part of this sentence to eliminate two answer choices: same.

There is no such thing as same like.

If you see the word same and your choices are same as and same like, always choose same as.

Correct: He asked the same question as I did.
Wrong: He asked the same question like I did.

Correct: Her eyes are the same color as her father's.
Wrong: Her eyes are the same color like her father's.

Correct: The briny solution is believed to possess about the same level of salinity AS the primordial sea possessed.
Options B and E incorrectly say: . . . about the same salinity like the primordial sea . . .
Eliminate options B and E

• Split #2: "thought to be about [without OF] . . ." is ungrammatical and illogical
In this context, the phrase "thought to be about" is ungrammatical and illogical because about means "nearly," and

In a logical sense, this split is probably easier than the from where/from which split.
The latter split is not as clear cut as it is described in places.

Comparing the three constructions in the options:
(A) is best; (C) and (D) are illogical.

Option C) is ungrammatical :
The solution is thought to be about the same salinity as the primordial sea . . .
-- the solution/a something cannot BE the same salinity as the sea.
Salinity is a noun. The briny solution is salty fluid. The briny solution is not salinity (saltiness) itself..
-- something can possess or have the same level OF salinity as the sea
Eliminate option C

Option D says, "The solution is thought of as about the same salinity as the primordial sea."
Option (D) is almost incoherent.
The first OF may make the reader believe that the sentence is correct.
Replace "about" with "nearly," which is what about means in this sentence.
(About is not a preposition. It's an adverb in this case.)

Option D: The solution is thought of as nearly the same salinity as the primordial sea.
-- "thought of" suggests that you or others conceive of the solution in certain way, as if thinking it were so could make it so.
-- "thought of" also suggests that you or others re-imagine the solution or ascribe to it a certain characteristic
-- Option D needs a verb or another OF, this way:

The solution is thought of as having nearly the same salinity as the primordial sea.
Or this way:
The solution is thought of as OF [= having] nearly the same salinity as the primordial sea.
(But that sentence sounds horrible. No wonder the author did not write it.)

At the least, option D is not as clear as option A.
Eliminate D.

The answer is A.

Check option A.
The tissues of the human body are constantly moistened by a briny solution thought to be of about the same salinity as the primordial sea from which life emerged.
Thought to be
-- . . . a briny solution thought to be OF about the same salinity as the primordial sea.
That construction is logical. Replace about with nearly.

-- . . . a briny solution thought to be OF nearly the same salinity as the primordial sea.
This phrase means that the briny solution is thought to HAVE the same [level of] salinity as the primordial sea.
The briny solution is believed to [be of = have] the same [level of] salinity as the primordial sea.
That construction is logical and grammatical.

• Split #3: from which is better than from where
Now, just to be sure, compare from where life emerged and from which life emerged.

Option A says, ". . . the primordial sea, from which life emerged."
From which modifies the primordial sea, not the salinity.
(From where and out of which also modify the primordial sea and not the salinity.)

The primordial sea was both a thing and a place, although the latter case is unusual.

As I noted below in response to a question, the primordial sea (the prehistoric sea) was a place in some sense.
For the average (non-biologist) speaker, this question is correct: From where did life emerge on Earth?
This answer is correct: From the primordial sea.
The question is literally from which place did life originate?
The answer is also literally about place.

But this sentence seems to focus on organic process.
The sentence is trying to connect fluids essential to human life to the origins of life.
The level of salinity is the same in human tears as the level is thought to have been in the primordial sea.

For processes, from which is better than from where.

For example:
During the Renaissance, all Venetian glassblowers were forced to live on the island of Murano, [i]from which came exquisite glass that fueled a city-state.
[/i]Murano is a place. But beautiful glass emerged from Murano not because it was an island but rather because glassblowers figured out a secret in the process of refining their glassmaking technique.
Glassblowers were confined to the island of Murano, from which emerged beautiful glass still held in esteem today.

. . . "the primordial sea, from which life emerged" is better than "from where."
Option A is better than D on that issue.

NOTES
• thought of as and thought to be do not mean the same thing.

• Thought of as suggests that you conceive of something you already know or are familiar with as a certain kind of thing or as having a certain quality.
You are not guessing. You are attributing.
I thought of my best friend as my sister.
-- I knew my best friend. I thought of her in a certain way. She was not my sister, but I thought of her as my sister.
He is thought of as the leader of the hiking group.
-- He is perceived in a certain way.

• Thought to be suggests that someone is fairly certain that something is the case.
Some speculation is involved, usually because the subject matter does not lend itself to "absolute" or scientific proof.

He is thought to be the worst leader in American history by most presidential historians.
These two are from LDOCE online (see below)
The sudden onset of severe weather conditions was thought to be a frequent result of disturbance to a site.
This downed electrical line was thought to be the cause of the blaze.

Thought to be suggests that you believe something to be the case, but you are not sure.
You are guessing.

We can't really think of the briny solution that moistens human tissues AS something; thought of as does not work.

You can read more about the difference in the Longman Dictionary of Contemporary English (LDOCE) online, here.

Takeaways
This question is hard, and comparison of options really helps.

Options B and E are easy to eliminate. Same never goes with like.

Options C and D both have weird or nonsensical "thought of as" and "thought to be of as" phrasing.
Both also use from where rather than from which.
Option A contains neither issue and is superior to both C and D.

COMMENTS

SonGoku , welcome to SC Butler.

This question is hard. I gave you all two days to answer (maybe three? I get times mixed up when I am as busy as I have been).

I wrote three OEs in the last 12 hours and I am about to post two more questions. (We are back on 24-hour reveal.)

This part is addressed to everyone, not just people who posted (or to lurkers whom I invite to post )
Don't worry too much about this question. It's just one question.
But do use it as a way to practice comparing options. Go back through the question.
What subtle differences did you miss?
Between and among which answers could you have asked, "Which is better? Which is worse"?

Today kudos go to correct answers with GOOD explanations.

Keep up the good effort.