Uranus and Neptune Are Similar in Size and Have Similar

Multiple Choice

Uranus and Neptune are similar in size and have similar atmospheres,but Neptune is significantly farther away from the Sun than is Uranus,by a ratio of about 30/19.What conclusion can be reached,therefore,from the fact that Neptune's temperature is about the same as Uranus's?

A) Neptune's atmosphere must contain a more effective greenhouse gas to maintain more solar energy.
B) Neptune must have a significant source of internal energy or heat.
C) The solar wind is able to penetrate to Neptune's cloud tops and deposit energy there,whereas Uranus's magnetic field deflects the solar wind.
D) Neptune is being distorted,therefore heating more than Uranus by tidal effects from Jupiter and Saturn.