One split we notice right away is between the simple past "G did not invent the telescope" and the past perfect "G had not invented the telescope". The past perfect is used for actions which began and ended in the past, prior to another past action. That does not apply here because the action 'did not invent' did not end in the past. Even as of right now, Galileo did not invent the telescope. Eliminate Past Perfect answers: B and C.

D is missing 'he' at the end. D's core states "Even though G did not invent...quickly built his..."

E is incorrect because the double negative "Even though...but" is redundant.

The answer is A. A more in-depth study and step-by-step video solution can be found at GMATPrep QID 2031. To create timed drills with similar questions, set topic='Verb Tense' and difficulty='700+' in the Drill Generator.

-Patrick

I drilled down to A and E.

E is wrong becase, usage of being and 1609 is without any preposition. what is 1609, year, number or what? If we have 'in' 1609, then it makes sense that 1609 is a year.

Therefore, I eliminated E.

Please correct me if I am wrong

Answer is A

gmatruler wrote:Galileo did not invent the telescope, but on hearing, in 1609, that such an optical instrument had been made, he quickly built his own device from an organ pipe and spectacle lenses.

A. Galileo did not invent the telescope, but on hearing, in 1609, that such an optical instrument had been made, he

B. Galileo had not invented the telescope, but when he heard, in 1609, of such an optical instrument having been made,

C. Galileo, even though he had not invented the telescope, on hearing, in 1609, that such an optical instrument had been made, he

D. Even though Galileo did not invent the telescope, on hearing, in 1609, that such an optical instrument had been made,

E. Even though Galileo did not invent the telescope, but when he heard, 1609, of such an optical instrument being made, he

I got A too.