Answer:
The correct answer is option A. "archegonium".
Step-by-step explanation:
An archegonium is a multicellular structure found on the gametophyte phase during the life cycle of certain plants, particularly, in ferns, mosses and some gymnosperms. The function of the archegonium is to produce and contain the ovum or female gamete. Therefore, an archegonium would always contain an egg cell.