In our lab exercise on the revolutions of the moons of Jupiter, you

graphed the positions of the moons (relative to Jupiter) as a function of time.  Which two properties of Jupiter's moons did you then measure using the graphs of the moon's positions?
            
            a. Period of moon's revolution and diameter (size) of moon
            b. Period of moon's revolution and mass of moon
            c. Period of moon's revolution and average distance of moon from Jupiter 
            d. Mass of moon and diameter of moon
            e. Mass of moon and average distance of moon from Jupiter