Which of the mathematical signs should be interchanged in the given equation to make it mathematically correct?
$$12 + 66 \div 11 − 4 \times 91 = 159$$

Option (a) $$\div$$ and $$\times$$

$$12 + 66 \times 11 − 4 \div 91 = 159$$
The above-given equation is not satisfied. Because it will give values in fractions. So this is not the correct answer.

Option (b) + and −

$$12 − 66 \div 11 + 4 \times 91 = 159$$

$$12 − 6 + 364 = 159$$

$$370\ne159$$

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

Option (c) + and $$\times$$

$$12 \times 66 \div 11 − 4 + 91 = 159$$

$$12\times6−4+91=159$$

$$72−4+91=159$$

Option (d) + and $$\div$$

$$12 \div 66 + 11 − 4 \times 91 = 159$$

The above-given equation is not satisfied. Because it will give values in decimals. So this is not the correct answer.