The correct answer is option D-the underside of the sporophyte.
Explanation:
Ferns are pteridophytes which evolved earlier than the flowering plants. They do not produce seeds and reproduce through spores.
These spores are usually present on the underside of fern leaf also called "fronds" in sporophytic structures called sori. When these spores are ripened they are released from the capsule which germinates to produce prothallus, a gametophyte from which gametes are produced.
Thus, option D-the underside of the sporophyte is the correct option.
The Grand Canyon is made of sedimentary rock that contains fossils up to 1 billion years old. and the several upper layers of rock contain terrestrial, or land-based, fossils, such as dragonfly wing impressions and the footprints of scorpions, centipedes, and reptiles
