The correct answer is letter A. Biosphere is not directly studied in one of the main branches of Earth/Space science. This is a branch of science that focuses on living organisms that are living in different populations or communities all over Earth. The other three choices directly study these branches of Sciences.
If you can't divide the number by 4, then it isn't divisible by 4. Try to divide 24, 8, 12, and 10 by 4. If your result isn't a whole number (like 2.4), then it isn't divisible by 4.
