If "$$-$$" and "$$\times$$" signs as well as "7" and "3" are interchanged, then which of the one following is correct?

A

$$20 \times 1 - 7$$ = 3

B

$$1 \times 20 -7$$ = 20

C

$$3 - 7 \times 1$$ = 20

D

$$20 - 3 \times 1$$ = 7