Direction: Complete the following sentence by selecting the correct option from the following.

For social interaction human beings depends primarily on ____________.

Passage 2

Man can speak, he has language. Animals have no language. Through the unifying force of language a mind, otherwise sunk in itself, combines with others. It is through speech that the mind I have is projected into other minds and those in turn become part of my own. When mankind learnt to preserve to language through the written word, the area of contact between minds was extended.