In which group of tracheophytes do sporangia develop individually on the upper surface of sporophylls, which may or may not be organized into strobili?

Explanation

In Lycopsida, the sporangia form singly on the upper side of sporophylls. These sporophylls can be either arranged to form strobili or remain separate. This distinguishes Lycopsida from other tracheophyte groups such as Psilopsida, Sphenopsida, and Pteropsida.