The seventh-grade class is building target areas for a PE activity. The bases for the game will be in a circular shape. The diameter of each circle is 3 feet. Approximately, how many square feet of the turf need to be painted for a base circle? Use 3.14 for π and round your answer to the nearest tenth.
a
7.1 square feet
b
9.4 square feet
c
18.8 square feet
d
28.3 square feet