From the words lettered A to D choose the word or group of words that best completes the sentence. After he had tried for sometime, he realized that all his...

Answer Details

The most appropriate word to complete the sentence is "futile". The word "futile" means useless, pointless or incapable of producing a useful result. In the sentence, the speaker has been trying for some time and has come to the realization that all his efforts are not going to produce the desired result. The word "futile" describes the situation where despite putting in effort, the outcome is not likely to be positive or productive. Therefore, the most suitable option to complete the sentence is "futile".