The above shows two spherical planets with different temperatures and sizes. The temperatures of planets A and B are K and K, respectively. The radii of planets A and B are and respectively. Which of the following statements is correct?
a) The wavelength of the electromagnetic wave that has the largest spectral radiance in the radiation emitted from planet B is three times longer than that from planet A.
b) The radiant energy per unit time and per unit area from planet A is times larger than that from planet B.
c) The total radiant energy per unit time from planet A is times larger than that from planet B.