Answer: A) Sweet potato
Explanation:
Sweet potatoes are the foods that are good source of beta carotene. These can slow down the progress of muscular degeneration. The body converts the beta carotene to vitamin A. The vitamin A will prevent the dry eyes and night blindness.
The sweet potatoes are the rich source of fiber, vitamins like B and C, calcium, and selenium. The sweet potato also act as an antioxidant due to the presence of beta-carotene.
On the basis of the above description, sweet potato is the correct option as it posses high nutrient value and can help in fighting against the night blindness.