What is the expanded form of this number?

15.306

1.(1×10)+(5×1)+(3×110)+(6×1100)

2.(1×10)+(5×1)+(3×1100)+(6×11,000)

3.(1×10)+(5×1)+(3×110)+(6×11,000)

4.(1×10)+(5×1)+(3×1100)+(6×1100)