Answer: 2) Terms of Use policy
Explanation:
Terms of service are a contract or agreement between the user of a website or in this case a social networking operator and the social networking operator itself. This agreement is meant to govern the terms of the relationship between the 2 parties in terms of what will be expected of both, i.e, their rights and responsibilities.
On the side of the social networking operator, one of the rights usually listed is one stating that the operator can collect and store data on users or even share it with third parties and so it is important to read the terms of use policy as best you can when you can.