Explanation:

Let's break down the expression step by step, using provided symbols:

- 'D' denotes division (÷), 'A' is addition (+), 'C' is subtraction (-), and 'B' is multiplication (×).

- Replace the letters with operators:

(84 ÷ 14) + 17 - 13 × (75 ÷ 15) + 9 × 7

- Calculate step-by-step:

1. 84 ÷ 14 = 6

2. 75 ÷ 15 = 5

3. Simplify expression:

6 + 17 - 13 × 5 + 9 × 7

4. Multiplications:

13 × 5 = 65,

9 × 7 = 63

5. Subtract and add from left to right:

6 + 17 = 23

23 - 65 = -42

-42 + 63 = 21

- Choose the option that matches the calculated result.

The correct answer is Option 4: 21.