The curve extends below the x-axis, so the added constant must be larger than the coefficient of the sine function. There are two choices matching that description.
The extent in the -y (θ=-π/2) direction looks to be about 2/3 of the extent in the +x (θ=0) direction, so we expect the appropriate equation is ...
Since we are using 3 sides of measurement and are looking for a volume, or a 3rd dimensional amount, the correct unit of measure is going to cm3, which is B.). I hope this helps!
