Bloodletting, the withdrawal of small quantities of blood fr

[BTGmoderatorAT]

Bloodletting, the withdrawal of small quantities of blood from a patient, as a procedure to prevent or cure illnesses, it was commonly performed by physicians until the late 19th century when they realized that it caused more harm than good.

A. as a procedure to prevent or cure illnesses, it was commonly performed
B. as a commonly performed procedure to prevent or cure illnesses
C. was a commonly performed procedure to prevent or cure illnesses
D. was a procedure to prevent or cure illness, commonly performed
E. had been a commonly performed procedure to prevent or cure illnesses

I'm confused between C and D. Can any experts help?

[Ali Tariq]

What's the source?
Text is quite similar to the following one-

Metallurgy, the process of refining metals from naturally mined ores, as a method of the moulding of metals, it was well known as early as the medieval period, but until about several decades ago workers did not realize that bacteria take an active part in the process.

(A) as a method of the moulding of metals, it was well-known

(B) as a method of the moulding of metals well-known

(C) was a well-known method of metal moulding

(D) was a well-known method of moulding metal that was

(E) had been a method of metal moulding, well-known

[ErikaPrepScholar]

Hey ardz24,

The key thing to notice is "by physicians" right after the underlined portion.

• Bloodletting, the withdrawal of small quantities of blood from a patient, as a procedure to prevent or cure illnesses, it was commonly performed by physicians until the late 19th century when they realized that it caused more harm than good.

A has some sentence structure issues, but it is clear that bloodletting is performed by physicians - in other words, "by physicians" describes "performed".

When we look at C, the order of the sentence is changed:

• Bloodletting, the withdrawal of small quantities of blood from a patient, was a commonly performed procedure to prevent or cure illnesses by physicians until the late 19th century when they realized that it caused more harm than good.

Now "by physicians" isn't next to "performed", so it isn't clear what "by physicians" is supposed to describe. D fixes the sentence structure issues in A *and* puts "performed" and "by physicians", making it a better choice.

A good rule of thumb on the GMAT: when something in a sentence describes something else in a sentence, we want to put those things as close together as possible.

[BTGmoderatorAT]

Thanks Erika! Such a great explaination

[ErikaPrepScholar]

No problem! Glad it helped.