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.
The Sahara desert is important for a multiple of reasons. One is that although it is a desert, there are many fertile areas of land making it great for farming and supporting life. It also acts as a natural barrier in between north and south Africa, which was able to impact trade with the South, slowing down innovation on both sides.
An indicator shows if the top of the map is north.
from quizlet.
