Why were the avatars embraced by the deity in Vaishnavism?

To save the world from disorder and destruction

The correct answer is Option 1 - To save the world from disorder and destruction

In the case of Vaishnavism, cults developed around the various avatars or incarnations of the deity. Ten avatars were recognised within the tradition. These were forms that the deity was believed to have assumed in order to save the world whenever it was threatened by disorder and destruction because of the dominance of evil forces. It is likely that different avatars were popular in different parts of the country. Recognising each of these local deities as a form of Vishnu was one way of creating a more unified religious tradition.