Explanation:

- The school has 1080 children: 560 boys and 520 girls.

- Chocolates are given in the ratio 1:2 (boys:girls).

- Normally, each girl gets twice as many chocolates as each boy.

- On Children's Day, 70 girls were absent; so 70 girls' chocolates went to the boys.

- Boys received 1 extra chocolate due to this redistribution.

- Let's calculate: if \( x \) chocolates per boy, then \( 2x \) for each girl.

- For 70 girls, \( 70 \times 2x = 140x \) chocolates were redistributed.

- 140x chocolates divided among 560 boys gives each boy 1 extra: \( \frac{140x}{560} = 1 \).

- Solving gives \( x = 4 \), so each boy receives 4 chocolates.

- Each girl receives \( 2 \times 4 = 8 \) chocolates.

- therefore, total chocolates = \( 560 \times 4 + 520 \times 8 = 2240 + 4160 = 6400 \).

The correct answer is:

- Option: 5 - 6400