In the following passage, at certain points you are given a choice of four words marked (a), (b), (c) and (d) one of which fits the meaning of the passage. Choose the best word out of the four: Mark the letter, viz., (a), (b), (c) or (d), relating to this word on your Answer sheet. Examples K and L have been solved for you. . He had kept on trying, and ____ could keep on trying, but ____ would become fewer and fewer.