In Mammalian Cells, Most Fatty Acid Elongation Occurs in _____________

In mammalian cells, most fatty acid elongation occurs in _____________. Most desaturation of fatty acids in mammalian cells occurs in _____________.

A) endoplasmic reticulum; mitochondria
B) Golgi apparatus; mitochondria.
C) endoplasmic reticulum; Golgi apparatus
D) Golgi apparatus; mitochondria
E) endoplasmic reticulum; endoplasmic reticulum