The correct answer is option 2: High wage. A pull factor refers to something that attracts people to migrate to a specific location. In the case of high wages, it means that people are drawn to move to a particular place because they can earn a higher income there compared to their current location. This is often associated with job opportunities that offer better pay and better living conditions.

Option 1: Natural disaster is not a pull factor for migration. Natural disasters such as earthquakes, floods, or hurricanes typically cause people to leave their homes and migrate out of necessity for safety reasons.

Option 3: Housing shortage is also not a pull factor. A housing shortage refers to a lack of available housing options in a specific area. It doesn`t attract people to move there, but rather can be a push factor, causing individuals to seek better housing opportunities elsewhere.

Option 4: Low income is another push factor rather than a pull factor. If people have a low income, it often leads them to migrate in search of better job opportunities and higher wages.

Therefore, the correct answer is option 2: High wage, as it attracts individuals to migrate in search of better economic prospects.