If ‘A’ stands for ‘÷’, ‘B’ stands for ‘×’, ‘C’ stands for ‘+’ and ‘D’ stands for ‘−’, then what will come in place of the question mark (?) in the following equation?
20 D 8 A 2 C 1 B 5 = ?

The correct option is 21.

To solve the given equation, we replace each letter with its corresponding mathematical symbol as defined in the question:
- A stands for ÷
- B stands for ×
- C stands for +
- D stands for −

Given equation:

$20D8A2C1B5=?$

Substituting the symbols into the equation gives:

$20-8÷2+1\times 5$

According to the order of operations (BODMAS/PEMDAS), we perform division and multiplication first from left to right:

Step 1: Perform Division
$8÷2=4$

Step 2: Perform Multiplication
$1\times 5=5$

Now, rewrite the equation with these results:

$20-4+5$

Step 3: Perform Subtraction and Addition from left to right
$20-4=16$
$16+5=21$

Thus, the value that replaces the question mark (?) is 21.