Female Corpse Floating in the Pond

On a hot summer day, a female corpse floated in the pond together with the garbage. The death was miserable and the smell was strong. Everyone in the village knew she was behaving erratically, so I quickly zeroed in on three suspects, but they all had alibis. But what's interesting is that all three of them have their own secrets hidden behind them. The murderer is among them, should I choose A? Choose B? Or choose C?