What is the most relevant detail for Camillo to provide to the police about the accident?

The detail regarding having the green light and being broadsided is the most relevant for the police because it directly addresses the circumstances surrounding the accident. This information is crucial for determining fault in the incident. By stating that he had the green light, Camillo indicates that he was following traffic laws and signals, which supports his position as a victim rather than a contributor to the accident. Moreover, being broadsided implies that another vehicle failed to obey traffic rules, likely running a red light or stop sign. This context helps law enforcement assess the situation accurately and assign responsibility accordingly.

While the other options contain useful information about the event, they do not provide as critical an insight into fault or legal accountability as the detail about the traffic signal. The intersection presence, knowledge of both drivers being unharmed, and the observation of the other vehicle's speed are less pertinent in establishing the legal implications of the crash. By focusing on the signal compliance, Camillo is providing a foundational element vital to any investigation regarding traffic incidents.