Which phrase correctly defines 'reasonable cause'?

The phrase that correctly defines 'reasonable cause' is based on a belief that aligns with the available evidence. This definition emphasizes the necessity of some level of justification or grounding in fact for an assumption or belief. In a legal context, reasonable cause, often referred to as "reasonable suspicion," means that a law enforcement officer has specific and articulable facts that would lead a reasonable person to believe that a crime may be occurring or has occurred. This is crucial because it establishes a threshold for actions like stops, searches, or further investigation, balancing the need for public safety against individual rights.

In contrast, the other options do not encapsulate the essence of reasonable cause as accurately. For instance, a clear indication that a crime has occurred is more definitive than what reasonable cause requires; it implies certainty rather than the necessary belief based on evidence. A strong hunch based on experience, while potentially leading to reasonable cause, does not provide the necessary factual basis that is essential. Lastly, a formal accusation is an assertion that typically comes after reasonable cause has been established, not a defining characteristic of it. Thus, option C effectively encapsulates the concept by highlighting its reliance on the correlation between belief and evidence.