If ‘A’ stands for ‘÷’, ‘B’ stands for ‘×’, ‘C’ stands for ‘+’ and ‘D’ stands…

Concept: When an expression mixes multiplication or division with addition or subtraction, the standard order of operations (BODMAS/PEMDAS) requires every multiplication and division to be carried out first, strictly left to right, and only afterward every addition and subtraction, again left to right.

1. Replace each letter in 56 A 8 D 7 C 3 B 6 with its assigned symbol: A → ÷, D → −, C → +, B → ×. The arrangement becomes 56 ÷ 8 − 7 + 3 × 6.

2. Scanning left to right, complete every multiplication and division first: 56 ÷ 8 = 7 and 3 × 6 = 18. The expression now reads 7 − 7 + 18.

3. Complete the remaining addition and subtraction left to right: 7 − 7 = 0, then 0 + 18 = 18.

4. The resultant of this arrangement is 18, which is exactly the value the question asks for.

Cross-check: decoding and evaluating the remaining three arrangements the same way confirms that none of them equal 18:

Since 56 A 8 D 7 C 3 B 6 is the only arrangement whose resultant equals 18, it is the correct answer.