Which two numbers should be interchanged to make the given equation correct?

$$5 - 4 \div 2 \times 10 + 7 = 7$$

Option (a) 10 and 2

$$5 - 4 \div 10 \times 2 + 7 = 7$$

$$5-0.4\times2+7=7$$

$$5-0.8+7=7$$

$$11.2\ne\ 7$$

The given equation is not satisfied. So this is not the correct answer.

Option (b) 5 and 7

$$7 - 4 \div 2 \times 10 + 5 = 7$$

$$7 - 2 \times 10 + 5 = 7$$

$$7 - 20 + 5 = 7$$

$$-8\ne\ 7$$

The given equation is not satisfied. So this is not the correct answer.

Option (c) 5 and 2

$$2 - 4 \div 5 \times 10 + 7 = 7$$

$$2 - 0.8 \times 10 + 7 = 7$$

$$2 - 8 + 7 = 7$$

$$1\ne\ 7$$

The given equation is not satisfied. So this is not the correct answer.

Option (d) 10 and 5

$$10 - 4 \div 2 \times 5 + 7 = 7$$

$$10 - 2 \times 5 + 7 = 7$$

$$10 - 10 + 7 = 7$$

7 = 7

The given equation is satisfied. So this is the correct answer.