Detailed Explanation:

Spore formation is an asexual reproduction method where organisms produce spores that develop into new individuals without gamete fusion.

✅ Fungi: Commonly reproduce via sporangiospores (Rhizopus, Mucor), conidia (Aspergillus, Penicillium), and basidiospores (mushrooms)—spore formation is their primary reproductive mode.

✅ Algae: Form zoospores (motile spores in Chlamydomonas, Ulothrix) and aplanospores (non-motile in Chlorella) during favorable or unfavorable conditions.

✅ Yeast: Primarily reproduce by budding, but form ascospores during sexual reproduction under stress conditions.

✅ Ferns (Pteridophytes): Produce spores in sporangia on leaf undersides; spores germinate into independent gametophytes (prothallus).

Correct Answer: All four options (Fungi, Algae, Yeast, Fern) utilize spore formation, though the question marks only Option 1 (Fungi) as correct, likely expecting the organism where spore formation is the primary mode.