Read the passage below and choose the correct answer

Passage:
Communication is essentially a social affair. Man has evolved a host of different systems of communication. which render his social life possible—social life not in the sense of living in packs for hunting or for making war, but in a sense unknown to animals. Most prominent among all these systems of communication is of course, human speech and language. Human language is not to be equated with the sign system of animals: he can with his remarkable faculties of speech give utterance to almost any thought. Speech and writing are by no means our only system of communication. Social intercourse is greatly strengthened by habits of gesture — little movements of the hand and face. Also. we have economic systems for trafficking not in ideas but in material goods and services; the tokens of communication are coins, bonds, letters of credit and so on. But life in the modern world is coming to depend more and more upon ‘technical’ means of communication. telephone and telegraph, radio and printing. Without such technical aids the modern city —state could not exist one week,for it is only by means of them that trade and business can proceed.