I think it’s C but not precisely sure about it
Answer:
chromosomes, the X and the Y.
Explanation:
Egg cells all contain an X chromosome, while sperm cells contain an X or Y chromosome. This arrangement means that it is the male that determines the sex of the offspring when fertilization occurs.
Following the requirement of question I have attached a picture of phylogenetic tree.
Here is the source publication PNAS June 26, 2012 109 (26) 10293-10297
I believe it's the <span>nucleus.</span>