Several environments in which you are more likely to find archaea than bacteria are

While archae can be found in virtually all environments similarly to bacteria, there are a few environments where they have been studied to be more abundant than bacteria. These habitats include the ocean floors (depths of over a meter), in planktons, and in saline waters ( salinities of over 20%). More archae are also found in sulfur-containing environments especially in hydrothermal vents on the ocean floors

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.