I believe the correct answer would be C. Sartorius i believe this is the answer, after doing some research on gO0gLe.
<span>Three months after fertilization and development of a placenta around the developing fetus, the corpus luteum regresses and forms the corpus albicans.</span> Formed placenta takes over progesterone production (which was the role of corpus luteum) and the corpus luteum degrades into a corpus albicans. The corpus luteum is being broken down by macrophages, in a process called luteolysis. The remains of the corpus albicans may persist as a scar on the ovary.
It's called merging cells. I don't understand why this is in Biology but whatever.