In London, peppered moths that were light colored blended in with trees of the
area, and were well populated. Over time, pollution caused the bark of the trees to darken, causing a
decrease in the number of light colored moths seen. The darker colored moths survived the predators
since they were able to blend in with the darkened tree bark and they reproduced rapidly.

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

it’s lava came from an explosive eruption

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.