Final Answer:
It possesses eusporangia, which are large, multicellular sporangia originating from several initial cells, distinguishing them from the one-celled leptosporangia found in most modern ferns. Therefore, the correct answer is option A) Eusporangium.
Step-by-step explanation:
Psilotum, commonly known as the Whisk Fern, exhibits a unique reproductive structure known as eusporangium. Eusporangia are large, multicellular sporangia characterized by their development from several initial cells, as opposed to the single-cell origin of leptosporangia. In eusporangiate plants like Psilotum, the eusporangium typically gives rise to numerous spores through meiosis.
Eusporangia are distinct from leptosporangia, which are smaller, one-celled sporangia common in most modern ferns. Understanding the type of sporangium in plants like Psilotum contributes to our knowledge of their reproductive strategies and evolutionary relationships.
The eusporangiate condition is considered more primitive, reflecting an earlier stage in the evolution of vascular plants. This distinction showcases the diversity of sporangial types in the plant kingdom, highlighting the fascinating evolutionary adaptations that have occurred over millions of years.
Therefore, the correct answer is option A) Eusporangium.