Which Is NOT a Reason That We Suspect Mars Once

Multiple Choice

Which is NOT a reason that we suspect Mars once had liquid water on its surface?

A) Mapping satellites have detected dry river beds.
B) Rovers have detected minerals that must have formed in the presence of liquid water.
C) Mapping satellites have detected outflow channels coming from impact craters.
D) The observed presence of water ice in Mars's polar icecaps.
E) All of the above are reasons.