shrutee 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 lense.

A)Galileo did not invent the telescope but on hearing in 1609,that such an optical instrument had been made This makes correct use of past perfect tense

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,onhearing,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,in 1609,of such an optical instrument being made,he this changes the meaning

GmatKiss wrote:IMO:A

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

, seems to be missing!

Please correct me if am wrong!