Read the reading below carefully, and then complete it with the best option A, B, C or D given below:
How men first learnt to create words is unknown; in other words, the origin of language is a (1) ______. All we really know is that men, unlike animals, somehow invented certain sounds to express thoughts and feelings, actions and things so that they could communicate with each other; and that later they agreed (2) ______ certain signs, called letters, which could be combined to represent those sounds, and which could be written down. These sounds, whether spoken or written in letters, are called words. Great writers are those who not only have great thoughts but also express these thoughts in words that appeal powerfully to our minds and emotions. This charming and telling use of words is what we call literary style. Above all, the real poet is a master of words. He can (3) ______ his meaning in words which sing like music, and which by their position and association can (4) ______ men to tears. We should, therefore, learn to choose our words carefully, (5) ______ they will make our speech silly and vulgar.

How men first learnt to create words is unknown; in other words, the origin of language is a (1) ______