#### Answer

The answer is (d) 6

#### Work Step by Step

When we add numbers, we include the significant figures up to the smallest number of decimal places in the numbers which are added.
4.56 has two decimal places.
9.032 has three decimal places.
580.0078 has four decimal places.
540.439 has three decimal places.
4.56 is the number with the smallest number of decimal places, since it only has two decimal places. Therefore, the final sum should be written with two decimal places.
When we add the four numbers together, the sum is 1134.04
The sum should be written with 6 significant figures.
The answer is (d) 6