The best source of Vitamin C is:

Apples are a good source of fiber and vitamin C. They also contain small amounts of other vitamins and minerals.

Mangoes are a good source of vitamins A and C. They also contain small amounts of other vitamins and minerals.

Milk is a good source of protein, calcium, and vitamin D. It also contains small amounts of other vitamins and minerals.

Here is a table showing the vitamin C content of 100 grams of each of the four foods:

| Food | Vitamin C content (mg) |
|—|—|
| Apple | 10 |
| Mango | 30 |
| Amla | 176 |
| Milk | 1 |

As you can see, amla has the highest vitamin C content of the four foods.