How does the matching of interests and hobbies contribute to forming friendships?

It creates a basis for shared activities and common ground

The correct answer is Option 4: It creates a basis for shared activities and common ground

While the NCERT also mentions reinforcement and validation of opinions, that explanation refers to similarity in attitudes and beliefs, not specifically hobbies and interests.

NCERT : "Similarity : Being exposed to someone over a period of time makes us assess our similarities and paves the way for formation of groups. Why do we like people who are similar? Psychologists have given several explanations for this. One explanation is that people prefer consistency and like relationships that are consistent. When two people are similar, there is consistency and they start liking each other. For example, you like playing football and another person in your class also loves playing football; there is a matching of your interests. There are higher chances that you may become friends. Another explanation given by psychologists is that when we meet similar people, they reinforce and validate our opinions and values, we feel we are right and thus we start liking them. Suppose you are of the opinion that too much watching of television is not good, because it shows too much violence. You meet someone who also has similar views. This validates your opinion, and you start liking the person who was instrumental in validating your opinion."