The answer is speciation by geographic isolation. When the population of a species gets separated due to reasons such as continental drift, mountains, canyons, etc. then each separated group of population may survive and adapt to their respective environment leading to speciation. These barriers do not allow the evolving populations to interbreed initially and over time when they evolve into different species they become completely reproductively isolated.
Well, DNA contains the hereditary information in the form of sequences of nucleotides which categorize as genes, that provide the information for synthesis of structural, functional and various other proteins that in combination and or in other ways determine an organism's complex traits. The phenotype of the said organism.
The correct answer is the last option.
The first option (unable to cause climate change) is incorrect because these gases do effect the atmospheric temperatures by increasing them.
The second option is incorrect because while these gases do cause more water vapor to condense, they result in acid rain (not wetter climates).