What must occur if an accused or complainant fails to appear at a hearing?

The correct choice indicates that if either the accused or the complainant fails to appear at a hearing, the Board has the discretion to either reschedule the hearing or continue with the proceedings based on the evidence and information that is available. This reflects the Board's responsibility to ensure that the process can move forward despite the absence of one party, thereby maintaining the efficiency and integrity of the legal proceedings.

By having the option to proceed with available resources, the Board can still address the issues at hand, potentially using testimony or evidence that does not rely on the absent party. This flexibility is crucial in legal contexts, as it allows for the possibility of achieving resolution without unnecessary delays caused by missed appearances.

In contrast, the other options would create unnecessary hurdles or delays in the judicial process. Canceling the hearing outright, dropping all charges, or adjourning indefinitely would not serve the interests of justice and would be impractical in maintaining the legal framework for hearings. Thus, the ability to either reschedule or continue with available resources is a crucial element of procedural law, ensuring that legal matters can be resolved in a timely manner.