What is a key characteristic of spores in terms of their longevity?

Spores are known for their incredible resilience and longevity in various environments. They possess a tough outer coating that allows them to withstand extreme conditions, including drought, temperature fluctuations, and even radiation. This adaptation enables many types of spores, including mold spores, to remain viable for extended periods—often over 20 years—under the right conditions.

The longevity of spores is significant because it illustrates their ability to persist in the environment until favorable conditions for growth return. This characteristic is crucial in understanding how mold can re-emerge or colonize a site after a disturbance, as viable spores may remain dormant until moisture and organic matter are present to support their growth.

In contrast, the other options suggest characteristics that are not aligned with the biological nature of spores. For instance, they do not decay rapidly; instead, they are designed to endure harsh conditions. While moisture is critical for spore germination and subsequent growth, it is not a requirement for their survival in a dormant state. Additionally, not all spores are necessarily viable, especially those that have been exposed to extreme conditions over time, which may lead to reduced viability.

Overall, option B accurately captures the enduring nature of spores, highlighting their remarkable ability to survive over long periods.