Answer : 2. "X-vitamin C, Y-iron, Z-citrus fruits"
Explanation :

Vitamin A deficiency can lead to night blindness and poor vision. B vitamins are a class of water-soluble vitamins. Vitamin B refers to several different types of vitamins that, together, are known as the B-complex vitamins. The commonly used Vitamin B Complex is constituted of 8 vitamins. Thiamin (vitamin B-1) Riboflavin (vitamin B-2) Niacin (vitamin B-3) Pantothenic acid (vitamin B-5) Vitamin B-6 Biotin (vitamin B-7) Folate (vitamin B-9) Vitamin B-12 Deficiency of Vitamin C can cause scurvy, a disease that is characterised by bleeding gums, skin spots, and swelling in joints. It also affects the immune system and can even be fatal in acute conditions. Vitamin C has been shown to enhance iron absorption. It captures non-heme iron and stores it in a form that's more easily absorbed by your body. Foods high in vitamin C include citrus fruits, dark green leafy vegetables, bell peppers, melons and strawberries. Citrus fruits are an excellent source of vitamin C. So from the above points, we can say that- 'X' = Vitamin C 'Y' = Iron (mineral) 'Z' = (Food) Citrus fruits