The Logic here is as follows:
20 – 10 means 200.
Therefore, "–" means "x".
20 x 10 = 200.

8 ÷ 4 means 12.
Therefore, "÷" means "+".
8 + 4 = 12.

6 x 2 means 4.
Therefore, "x" means "–".
6 – 2 = 4.
Now, [(100 – 10) × (1000 ÷ 1000)] ÷ (100 × 10)

Interchange the values in the given equation,
= [(100 x 10) – (1000 + 1000)] + (100 – 10)
= [(1000) – (2000)] + 90
= [-1000] + 90
= -910

Hence, the correct answer is "-910".