All living things on Earth are alike because, even though there are a lot of different adaptations which have result in different morphologies, structures and physiological mechanisms, they all contain the same five kinds of nucleotides, but the sequence of nucleotide bases that conform the genes is different.
Only photosynthetic organisms use energy from the sun to make food, and although most of the organisms are aerobic, there are also some anaerobic.
So the correct answer is option C: contain the same five kinds of nucleotides.