No black peppered moths have been found before 1845. where did this black moth came from? why was black moth not found before

in 1845 was around the time the industrial revolution began, so when this happened the black smoke coming from the factories turned most of the trees a darker color. which in turn caused a population shift since the dark peppered months were now the ones less frequently preyed on.

the answer for this question would be d. glaciers

wait any answer choices plz