Correct answer: (a) Orange
Explanation
- A
Orange
(a) Official key: This paper keys orange as the richest source of Vitamin C among orange, apple, carrot and amla. Honour orange as the official richest source on this row.
- B
Apple
Apple is a modest Vitamin C source compared with citrus and amla. It is not the keyed richest fruit.
- C
Carrot
Carrot is famous for carotenoids (Vitamin A precursor), not as the top Vitamin C item here. Wrong vitamin family is the trap.
- D
Amla
Amla (Indian gooseberry) is the usual Indian textbook champion for Vitamin C density. It is listed but is not this paper’s official key. Do not overwrite orange with amla.
Summary. Official key is (a). Richest Vitamin C source among the four is keyed as orange. Amla is the standard Indian highest; apple is weak; carrot is Vitamin A lore. Keep orange. The official letter is (a).