The correct answer to the question is option 1, which is butter. Butter is considered to be the poorest source of vitamin A among the given options. Butter is primarily made up of milk fat and does not contain a significant amount of vitamin A. While butter may contain trace amounts of vitamin A, it is not a reliable or concentrated source of this nutrient.

Fish, on the other hand, is a good source of vitamin A. Certain types of fish, such as salmon and mackerel, contain high levels of this vitamin. Ripe mango and ripe papaya are also good sources of vitamin A. These fruits are known for their vibrant orange or yellow color, which indicates a high content of beta-carotene, a precursor to vitamin A.

It is important to note that although butter may not be a rich source of vitamin A, it does contain other essential nutrients. However, if one is looking to increase their intake of vitamin A, it is advisable to choose other options such as fish, mango, or papaya.