Which two signs and two numbers should be interchanged in the following equation to make it correct?
$$60 \times 3 + 660 \div 6 - 20 = 290$$

A

$$6 and 660, $$\times$$ and $$\div$$

B

$$20 and 6, $$+$$ and $$-$$

C

$$20 and 60, $$+$$ and $$\times$$

D

$$20 and 660, $$+$$ and $$\div$$