Although it’s clear that Mars once had liquid water on its surface, astronomers have debated whether the evidence of ancient water reflects a prolonged phase of warm, wet conditions—the so-called wet and warm scenario—or a brief period of melting in an otherwise consistently frozen environment. Researchers Benjamin T. Cardenas and Michael P. Lamb recently added to this debate by using data from NASA and the Mars Orbiter Laser Altimeter to map the topography of what is now a large basin in Mars’s northern hemisphere. Cardenas and Lamb concluded that the wet and warm scenario is likely correct.

Which finding about the basin, if true, would most directly support Cardenas and Lamb’s conclusion?
Choose 1 answer:
Choose 1 answer:
(Choice A) Its physical characteristics are most consistent with it having formed as a result of a massive but short lived influx of liquid water.
A
Its physical characteristics are most consistent with it having formed as a result of a massive but short lived influx of liquid water.
(Choice B) It is surrounded by channels that could have been formed either by running water or by flowing lava.
B
It is surrounded by channels that could have been formed either by running water or by flowing lava.
(Choice C) It has features suggesting that it once held an ocean that underwent gradual sea-level changes over an extended time.
C
It has features suggesting that it once held an ocean that underwent gradual sea-level changes over an extended time.
(Choice D) Its dimensions and shape indicate that it is unlikely to have formed as the result of an asteroid or comet impact.
D
Its dimensions and shape indicate that it is unlikely to have formed as the result of an asteroid or comet impact.

(Choice A) Its physical characteristics are most consistent with it having formed as a result of a massive but short-lived influx of liquid water.

This finding would directly support Cardenas and Lamb's conclusion that the wet and warm scenario is likely correct, as it suggests that the basin was formed by a significant amount of liquid water entering the area in a short period of time, rather than gradual or minor water flows.