What Advantages Are There to Synthesizing a Naturally Occurring Medicine

What advantages are there to synthesizing a naturally occurring medicine, such as Taxol, in the laboratory rather than isolating it from nature?

A) Synthesizing a natural product can be advantageous when the source of the natural product is rare and thus not readily available.
B) In synthesizing the natural product in the laboratory, the chemist is able to create closely related compounds that may have even greater medicinal properties.
C) In synthesizing the natural product in the laboratory, a chemist can increase the concentration of the synthetic beyond that of natural product to insure maximum potency for good health.
D) Both A and B are true.