Which of the following contributes to mars’ cool temperatures? this is for astronomy.

its thick atmosphere and distance from the sun

mars does not have cool temperatures. it is a very warm planet.

its thin atmosphere and distance from the sun

its thin atmosphere and closeness to the sun

The answer that contributes to Mars's cool temperatures is the third choice - Its thin atmosphere and distance from the Sun.
Mars is relatively distant from the Sun - it is the fourth planet away from the Sun which means that it can be quite cold there given that its atmosphere is quite thin which means that the cold is quite present there.

Long term continuous groundwater monitoring, especially with warning systems and anthropic activity monitors