Why Are Biotechnology Companies Eager to Design Genetically Modified Organisms

Why are biotechnology companies eager to design genetically modified organisms to express therapeutic proteins,particularly ones that would otherwise have to be isolated from blood products (e.g. ,human antithrombin) or animal organs (e.g. ,insulin,originally isolated from pig pancreas) ?

A) Biotechnology companies want to produce therapeutic proteins in the most cost-effective way.
B) There are safety concerns when using proteins from different species or isolating proteins from humans.
C) It is difficult to collect enough of some low-abundance proteins.
D) Biotechnology companies are generally not interested in genetically modified organisms because it is not a profitable or marketable technology.
E) Biotechnology companies are interested in the cost-effectiveness,safety,and efficiency of protein production.