one requirement for a planet to support earth-type life is that it be considerably larger than mars. what is the reason for this requirement? select an answer and submit. for keyboard navigation, use the up/down arrow keys to select an answer. a it is necessary for liquid water to exist on the planet's surface. b it is necessary for the planet to retain all of its carbon. c it is necessary for the planet to have active plate tectonics to close its carbon cycle. d it is necessary for the planet to retain oxygen in its atmosphere.