Which of the following is a type of spore-bearing fungus often found growing in yards on moist days?

Mushrooms are a type of spore-bearing fungus and are commonly found in various environments, including yards, especially on moist days. They release spores into the air and the surrounding ground, which can lead to new mushroom growth in favorable conditions. Mushrooms typically thrive in damp environments, as moisture encourages spore germination and growth.

Algae, while living in moist areas, are photosynthetic organisms and not fungi. Lichens are complex organisms that arise from a symbiotic relationship between fungi and algae or cyanobacteria, not just fungi alone. Truffles are a specific type of fungus that grow underground in association with tree roots and are not typically found above ground like mushrooms. These distinctions clarify why mushrooms are the best answer in this context.