Sentence Correction - synthetic growth hormone

[Xbond]

Hi there,

I would like to know how to proceed in order to resolve this SC :

Before scientists learned how to make a synthetic growth hormone, removing it painstakingly in small amounts from the pituitary glands of human cadavers.

(A) scientists learned how to make a synthetic growth hormone, removing it painstakingly
(B) learning how to synthesize the growth hormone, it had to be painstakingly removed by scientists
(C) scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly
(D) learning how to make a synthetic growth hormone, scientists had to remove it painstakingly
(E) scientists learned how to synthesize the growth hormone, it had to be painstakingly removed

[tohellandback]

IMO E

(A) scientists learned how to make a synthetic growth hormone, removing it painstakingly -sounds Incomplete
(B) learning how to synthesize the growth hormone, it had to be painstakingly removed by scientists - sounds like hormone had to learn something
(C) scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly - [color=red]wordy
[/color]
(D) learning how to make a synthetic growth hormone, scientists had to remove it painstakingly -it refers to synthetic growth hormone. But the growth hormones we painstakingly removed and not the "synthetic growth hormones". Changes meaning
(E) scientists learned how to synthesize the growth hormone, it had to be painstakingly removed- [color=red]Correct[/color]

[vikram_k51]

Before scientists learned how to make a synthetic growth hormone, removing it painstakingly in small amounts from the pituitary glands of human cadavers.

(A) scientists learned how to make a synthetic growth hormone, removing it painstakingly
(B) learning how to synthesize the growth hormone, it had to be painstakingly removed by scientists
(C) scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly
(D) learning how to make a synthetic growth hormone, scientists had to remove it painstakingly
(E) scientists learned how to synthesize the growth hormone, it had to be painstakingly removed

[enniguy]

You can't remove a synthetic growth hormone. (You can only remove a growth hormone). So A, C, D out.
B - Scientists need not remove it. They just learned about it.

Hence, E.

[Xbond]

the right answer is E

[shahdevine]

Hi there,

I would like to know how to proceed in order to resolve this SC :

Before scientists learned how to make a synthetic growth hormone, removing it painstakingly in small amounts from the pituitary glands of human cadavers.

(A) scientists learned how to make a synthetic growth hormone, removing it painstakingly
(B) learning how to synthesize the growth hormone, it had to be painstakingly removed by scientists
(C) scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly
(D) learning how to make a synthetic growth hormone, scientists had to remove it painstakingly
(E) scientists learned how to synthesize the growth hormone, it had to be painstakingly removed

D

"learning how to make..." perfectly modifies scientists in subsequent clause.

stand corrected. e

[Xbond]

I wrote that OA was E