His left arm still dangled in the water , and the thing- whatever it was he 'd mistaken for a fish , was still holding it . The light bounced in ripples over its body , illuminating it , but it was n't for another long moment that Atobe saw the tail . " Thank you , " Atobe mouthed to it and its eyes flicked , watching his face , trying to understand . It ... he , whistled and tugged gently on his arm .

Question: What may be the reason the animal held on to his arm ?
Answer: None of the above choices .It might have wanted to give him a high five .It might have though his arm was his father .It might have wanted him to pet in in the water .