womb is a noteworthy female hormone-responsive auxiliary sex organ of the conceptive framework in people and most different well evolved creatures. In the human, the lower end of the uterus, the cervix, opens into the vagina, while the upper end, the fundus, is associated with the fallopian tubes.
I think it is A but not 100% sure. Think of an enzyme like a key unlock the lock is the protein. And to activate getting inside your car or house you have to fit the key into the lock.
