I believe the answer would be Letter
B. Psychology
Immune System. Its like the Army for your body!
Oils and fats are types of lipids.
Genetic material is found in Eukaryotic cells. Plant and animal cells both are eukaryotic cells.
It is a cold Artic air mass over Siberia. Air masses are altered because it doesn't stay in one place and changes as it moves due to the temperature of environment that can be caused by moisture. The cold Artic Mass from Siberia will go to the North Pole, Canada then moves further to the South area.
