The Mars Exploration Rovers Were Both Landed at Locations That

The Mars Exploration Rovers were both landed at locations that seemed promising for uncovering evidence of ancient water flow on Mars. What did they find?

A) As expected, both found sedimentary rocks, evaporites, and hematite, all signs of abundant water on the Martian surface in the past.
B) Neither rover discovered any signs that water had ever existed on the surface of Mars.
C) Spirit found abundant signs, including pools of liquid water, that water exists at present on the Martian surface, while Opportunity found none.
D) Spirit found few signs of past water flow but Opportunity found sedimentary rocks, evaporites, and hematite, all signs of abundant water on the Martian surface in the past.