Select the correct combination of mathematical signs to sequentially replace the % signs and to balance the given equation.
[{(32 % 28) % (6 % 4)} % (1 % 7)] % 5 % 20
1
-, +, ×, ÷, ×, ×, =
2
×, ÷, ×, ×, -, +, =
3
×, -, +, ×, ÷, ×, =
4
-, +, ×, ×, ×, ×, =