The correct answer is Option C. The swan is injured and in pain.
Since the swan was found entangled in thorns struggling and moaning, it is inferred the swan was clearly in pain and crying for help. Animals act on instinct, and since the swan was in the midst of pain, its instincts found the surroundings as potential threats - that includes the thorns and everything in the vicinity, even Mr. Peters trying to help. Thus, the swan attacked Mr. Peters, mistaking him for a threat.
