Concept:To add decimals, align the decimal points and add trailing zeros to make all numbers have the same number of decimal places. This ensures each place value is added correctly.Explanation:First, write each number with three decimal places by adding zeros: 245.36 becomes 245.360, 12.475 stays 12.475, and 98.24 becomes 98.240. Now add them vertically by aligning the decimal points:245.360+12.475+98.240Add the thousandths column: 0+5+0=5.Add the hundredths column: 6+7+4=17, write 7 and carry 1 to tenths.Add the tenths column: 3+4+2+carry 1=10, write 0 and carry 1 to units.Add the units column: 5+2+8+carry 1=16, write 6 and carry 1 to tens.Add the tens column: 4+1+9+carry 1=15, write 5 and carry 1 to hundreds.Add the hundreds column: 2+0+0+carry 1=3.The sum is 356.075.Answer:356.075 (Option A)