Identify the class boundaries for the following frequency distribution:

Age (yr) when award was won

- 15 to 19: 31
- 20 to 24: 32
- 25 to 29: 16
- 30 to 34: 2
- 35 to 39: 4
- 40 to 44: 2
- 45 to 49: 1

A) 14.5 to 19.5, 19.5 to 24.5, 24.5 to 29.5, 29.5 to 34.5, 34.5 to 39.5, 39.5 to 44.5, 44.5 to 49.5
B) 15 to 19, 20 to 24, 25 to 29, 30 to 34, 35 to 39, 40 to 44, 45 to 49
C) 15.5 to 18.5, 20.5 to 23.5, 25.5 to 28.5, 30.5 to 33.5, 35.5 to 38.5, 40.5 to 43.5, 45.5 to 48.5
D) 15 to 20, 20 to 25, 25 to 30, 30 to 35, 35 to 40, 40 to 45, 45 to 50