The correct option for matching the given organisms with their respective categories is option 2. The correct matching is as follows:
A- Anabaena: Blue-green algae (also known as cyanobacteria)
B- Mucor: Fungi
C- Pseudomonas: Bacteria
D- Ephedra: Gymnosperm
Option 1 incorrectly matches Anabaena with bacteria, Mucor with gymnosperm, Pseudomonas with fungi, and Ephedra with blue-green algae.
Option 3 incorrectly matches Anabaena with fungi, Mucor with bacteria, Pseudomonas with gymnosperm, and Ephedra with blue-green algae.
Option 4 incorrectly matches Anabaena with gymnosperm, Mucor with bacteria, Pseudomonas with blue-green algae, and Ephedra with fungi.
Therefore, the correct option is option 2.