GMAT question please(critcal reasoning) On pacific islands,a newly arrived gecko species,the house gecko,is displacing the previously established mourning gecko in urban areas,but popluations of the two species are more stable in rural areas far from human settlement.the house gecko does not attack the mourning gecko,but in areas where insects congregate it prevents the mourning gecko from feeding on them. Which of the following contributes most to an explanation of the difference between gecko populations in urban and rural areas? A.In urban areas,gecko are valued because they eat so many insects. B.Gecko defend territories agasint other members of the same species. C.House geckos that arrive on islands are carried there in boats and planes. D.In places where there are lighted buildings,insects tend to gather around the light. E.Mourning geckos are all females,and reprouduce asexually,but house geckos reproduce sexually. The correct answer is D but I just don't know why.