Which describe what will mostly happen to the trout population

Trout is a very common freshwater fish. The lifespan is very small.  

Explanation:

The trout population is affected by the climate change and also the pollution present in the freshwater. These fish variety travel for across to lay eggs. And after laying eggs they just die. The climate change and the the fishing of this variety has negatively affected the population. There are lot of varieties of trout fish like rainbow albino etc.

The rise in temperature and flood in a river is a major factor which effects the population of this fish. in USA when the temperature rises it result in flood condition in the river which affects the lifestyle of this fish.

i think that d. wind is the answer.   i missed the question when i answered a. currents.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).