The doctor’s real mistake, from the perspective of his _______ professional friends who quickly jilted him, was not that his choice of treatment was inappropriate, but rather that it was viscerally objectionable to the medical establishment.

The establishment is who sets the standards

So , who pointed out the doctor was wrong, belong to this establishment.

therefore = orthodox

B and D are the correct answers

Now that I know what stodgy means, I have a doubt. The doctor's friends quickly abandoned him, sure, so with that perspective they are fickle and inconstant.
But, when we read further, the reason for the betrayal is given, the doctor's actions were objectionable to the medical establishment. In that sense, his friends were supporters of orthodox views. So answer can be orthodox and stodgy also right?

Please help me.

Carcass I think your explanation seems to ignore the fact that when you mentioned "therefore = orthodox", the options should naturally come down to E and F.

Can you deem what's fit in this context and change the options if required?

Thank you for your service as always

Explanation

The key clue in the sentence is the phrase "who quickly jilted him" - meaning his professional friends abruptly abandoned or betrayed him. The blank must describe the kind of friends who would do that: friends who are unreliable, changeable, and lacking in loyalty.

Fickle = changing frequently, especially in loyalties or affections; unreliable.
Inconstant = not constant; changeable; unstable in allegiance.


Both words perfectly describe friends who quickly desert someone, and they are direct synonyms, fulfilling the GRE Sentence Equivalence requirement.

Why the Others Are Incorrect

A. squeamish - means easily disgusted or queasy. While someone might be squeamish about a medical treatment, this does not explain the betrayal or abandonment.
C. staunch - means loyal and committed. This is the opposite of what is needed; a staunch friend would not have jilted him.
E. orthodox - means following conventional standards. While the doctor's treatment might have been unorthodox, the sentence focuses on the friends' action of abandoning him-the word "jilted" explicitly points to disloyalty, not just conventionality.
F. stodgy - means dull or old-fashioned. This does not pair with any other word and does not explain why they would quickly abandon him.