The answer to each of the following question is a single interger, ranging from 0 to 9 If the correct answers to questions, numbers A,B,Cand D say are 4,0,9 and 2, then the correct darkening of bubbles should be as shown on the side
(A) CO is a pollutant produced due to incomplete combindaation of butane. one mole of butane requires 6.5 moles of `O_(2)` for complete combustion .If 6 moles of oxygen are available , the number of CO produced will be

Answer

a