The volume of the composite figure is given by
Volume = Volume of Hemisphere + Volume of Cylinder
Volume of Hemisphere
This can be calculated by

The radius is 3 ft (half of the diameter)
Hence,

Volume of Cylinder
This can be calculated by

The radius is 0.75 ft (half of the diameter)
The height is 6 ft
Hence,

Therefore, the volume of the composite figure will be calculated by

The volume of the composite figure is 67.15 cubic feet.
The SECOND OPTION is correct!