Final answer:
Biological plausibility refers to whether an explanation or hypothesis in biology makes sense given biological systems and processes. The germ theory of disease is a historical example of an explanation that was eventually supported by repeated testing and known biological mechanisms.
Step-by-step explanation:
An example of biological plausibility is B. Theoretical mechanisms supporting a causal relationship. This concept is related to the idea that any explanation or hypothesis in biology should make sense given what is known about biological systems and processes. For instance, the germ theory of disease clearly illustrates biological plausibility, proposing that microorganisms are the cause of many diseases, which was supported by extensive research and repeated testing over centuries. This theory aligns with biological plausibility because the biological mechanisms of how germs cause disease are well-understood.