Originally Posted by usman khalid

Sociology is study of society. Population Explosion is one of the social issues. Many other issues we come across in our daily lives are social issues. Therefore, it is understood that the given passage talks about some social issue for which one doesn't need to explicitly mention the word 'sociology' in the title. However, even if it is included it doesn't mean that its a bad title. Remember, there may not be any fixed title to the passage or there may be as many titles as the no. of candidates!