It is possible to take a mature fern frond and rub the circular brown growths on the lower surface over a wet plug of peat moss.Soon small heart-shaped green structures grow on the nutritious peat moss plugs.What has happened?

A)Eggs and sperm released from the underside of the fern frond united on the peat plug and grew into sporophyte prothalli.
B)Spores released from the underside of the frond germinated on the peat plug and formed the gametophyte called a prothallus.
C)Spores released from the underside of the fern frond germinated on the peat plug and formed sporophyte rhizomes that give rise to many indusium.
D)Gametes released from the underside of the fern frond germinated on the peat plug and formed a sporophyte structure called an archegonium.
E)Zygotes released from the bottom of the fern frond germinated on the peat plug and grew into gametophyte fiddleheads.