Final answer:
Mars is shown to be a desolate and dying planet due to loss of atmosphere and drying up of surface water, becoming uninhabitable with no significant liquid water left.
Step-by-step explanation:
Based on the information provided regarding Mars's conditions and potential human colonization, the answer to the student's question is c) It is a desolate and dying planet. Mars, after epochs of warmer and wetter conditions suitable for life, lost much of its early atmosphere. This led to the drying up of surface water, and the remaining water became saltier and more acidic. Eventually, Mars was left with no significant liquid water on its surface, exposing it to harsh solar radiation and becoming uninhabitable. However, it remains an interesting candidate for human habitats outside its surface environment due to its past habitability and ongoing discoveries.