Answer: Whether the doors and windows in the room were open or closed.
Explanation:
A first responder is a officer who reaches at the crime scene for the first time and conducts the investigation. Such officer notices the condition of the crime scene, makes notes, documents the crime scene by taking photographs and sketches.
According to the given situation, Whether the doors and windows in the room were open or closed. is the correct option.
This is because of the fact that this will help him identify whether it was a homicide. As if the old man could have killed himself the doors and windows will be closed. But if the doors and windows were found to be open this indicates that the criminal could have used the doors and windows to escape.