Please choose the correct answer to the question: In the Adirondack forests of New York, some trees have died. The change in the forest is thought to be related to air pollution and rain. Which abiotic factor most likely has been changed as a result of the pollution and rain which resulted in the death of the trees?

Answer1: a decrease in the amount of available oxygen Answer2: an increase in the amount of sunlight Answer3: a decrease in the pH of the soil Answer4: an increase in soil nutrients

Answer format: answer1/answer2/answer3/answer4
Answer: answer3