The correct answer is option 3: p-carotene and iron. "Golden Rice" is a genetically modified variety of rice that has been engineered to produce high levels of beta-carotene, which is a precursor to vitamin A. This is done by introducing genes from other organisms that are capable of producing beta-carotene, such as daffodils or bacteria. Beta-carotene gives the rice its distinct golden color.

Option 1, which suggests that "Golden Rice" is rich in vitamin A and nicotinic acid, is incorrect. Nicotinic acid, also known as niacin, is not typically found in "Golden Rice" and is not one of the key nutrients targeted in the genetic modification process.

Option 2, which states that "Golden Rice" is rich in p-carotene and folic acid, is also incorrect. Folic acid is not naturally present in rice, and the genetic modifications in "Golden Rice" do not enhance its production.

Option 4, which suggests that "Golden Rice" is rich in vitamin A and niacin, is incorrect. While "Golden Rice" is indeed high in beta-carotene, which can be converted to vitamin A in the body, it does not contain niacin.

Therefore