9.Which set of rules represents the correct "order "for adding and subtracting decimals?
A. 1. Bring down the decimal
2. Line up the decimal
3. Subtract
4. Fill in the spaces zeros

B.1.Line up the decimal
2.Fill in the spaces with zeros
3.Subtract
4.Bring down the decimal

C.1.Subtract
2.Bring down the decimal
3.Fill in the spaces with zeros
4.Line up the decimal

D.1.Fill in the spaces with zeros
2.Subtract
3.Bring down the decimal
4.Line up the decimal