Once the physiological effects and anesthetic qualities of diethyl ether were demonstrated
and with its superiority to chloroform being proved by William Morton, the medical community rapidly adopted it as the anesthetic of choice.
(A) and with its superiority to chloroform being
(B) and its superiority to chloroform
(C) and its superiority over chloroform had been
(D) its superiority over chloroform
(E) with its superiority to chloroform having been
Explanation:In the original underlined phrase, major error is the use of incorrect verb tense i.e. 'being proved'.
This sentence describes a series of past events:
1. The physiological effects of diethyl ether were demonstrated
2. William Morton proved ether's superiority
3. The medical community adopted ether
Since the second event happened before the third event, past perfect tense should be used ("had been proved") to indicate that.
From the option we see that only option C uses the correct tense of the verb i.e. 'had been' while the rest don't.
(A) and with its superiority to chloroform being :
WRONG(B) and its superiority to chloroform:
Incomplete clause, missing 'was' proved. Also verb tense incorrect. WRONG(C) and its superiority over chloroform had been:
CORRECT(D) its superiority over chloroform:
Same error as in option B. WRONG(E) with its superiority to chloroform having been:
Verb tense incorrect. WRONGHence Option C is the correct choice.