Raxit85
Robert H. Goddard, recognized as one of the founding fathers of rocketry, holds the patents for the discovery of liquid-fueled and multi-stage rockets, but rarely acknowledged until the dawn of the space age.
Crux of the question - "but" is used to join two independent clauses
The part before "but" is an independent clause, hence the part of thr sentence after "but" has to be an independent clause - subject + verb
A. but rarely
- lacks a subject.
- acknowledged acts as a modifier in absence of a helping verb
B. was rarely
- the part before underlined portion is an independent clause. In absence of "FANBOYS", the structure joins to IC with comma - wrong
C. but had rarely been
- As mentioned in choice 1 analysis, this structure lacks a subject.
- in addition to that, present perfect tense is not required and does not make sense
D. which had rarely been
- "which" refers to the noun before comma - multi-jet rockets - such a reference completely distorts the meaning of the sentence.
E. but he was rarely
- "but" is used for connecting two independent clauses
- presence of a subject "he" - correct
- "was acknowledged" - correct tense
- Answer
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