Using your results from (b) and (c), is it possible to determine the size of Eris? If yes, how does it compare with Pluto (r_Pluto = 1185 km)?
a) Yes, Eris is smaller than Pluto.
b) Yes, Eris is larger than Pluto.
c) No, it's not possible to determine the size of Eris.
d) None of the above.