Each Sunday, Mario weighs himself. Here are his weight changes over a 4-week period.

Week: 1 2 3 4
Weight Change
(In pounds) -2.1 0.3 -1.7 -0.4

Adding Decimals How much has Mario’s weight changed over the entire 4 weeks?

A. –3.9 pounds

B. 5.4 pounds

C. 3.2 pounds

D. –4.1 pounds