On the Basis of Its Appearance and General Properties, Which

On the basis of its appearance and general properties, which planetary body could be described as Earth's twin?

A) Mars; somewhat smaller but with a similar surface, a thin atmosphere, and clouds
B) Moon; somewhat smaller but having the same average density and geology
C) Pluto; similar size and density, a large moon, and probably life on its surface
D) Venus; about the same mass and diameter, dense atmosphere, and cloud-shrouded