IBPS RRBs Officer Scale II and III Sep 2013 Paper

(4)
The meaning of the wordInstrumental (Adjective) as used in the passage is % important in making something happen.
Look at the sentence :
He was instrumental in bringing about an end to the conflict.
Of the given alternatives, the word Responsible (Adjective) means% being able to be blamed for something; being the cause for something.
Look at the sentence : Cigarette smoking is responsible for about 90 per cent of deaths from lung cancer.Hence, the words instrumental and responsible are synonymous.