C. Permafrost
Permafrost is the layer beneath the "active layer". The active layer consists of soil that freezes and thaws every year. However, the requirement for permafrost is that it be frozen for two or more years consecutively. This is why permafrost exists in cold environments such as tundras.
Leukopenia means a low count of white blood cells in the body. When there is a low white blood cell count in the body, and in particular a low level of neutrophils (a kind of white blood cell that fights infection), there is quite a significant risk of developing an infection, and once an infection is developed and the white blood cell count is low, the body will not be able to protect itself and fight off the infection. In severe cases , infection may lead to death.
Isotretinoin maybe responsible for depression for depression and suicidal thoughts in the patient. Isotretinoin is very useful against acne, but it can have some severe side effects. Aside for the ones mentioned above, Isotretinoin can also cause birth defects in new-born babies if taken by pregnant women. Liver functionality and cholestrol levels might also be affected, so it is advised to use this medication only under extreme supervision of the doctor.
metaphase I'm not sure but I think it is the answer
