Answer:
The answer is C homologous chromosomes
Humans, when exhaling release carbon which helps them to make sugar, and as a biproduct plants release oxegen which humans inhale.
I don't know if this helps or not but you would want to know the age of the rock (absolute dating) and from there you will be able to know the age of the fossil and what caused it to die.
I would say that the most likely environment for these two rock types to be ridge formers would be an arid climate like a desert where there was little water to dissolve. Also, even in a normal temperate environment, dolomite can form a very resistant ridge or cliff former as is the case with the Palliser Formation in Banff Park which forms a pronounced cliff which is very extensive.
