Answer:
He should aim below 40°
Step-by-step explanation:
Because
His eyes are being deceived about the real location of the fish, because the light coming from the fish is refracting away from the normal, if traced from the vertical as it passes into the air and to his eye . so, he will perceive the fish as being shallower than it really is. So if he throws the spear which will travel in a straight line directly at where he perceives the fish to be, the spear will pass above its head so he needs to need to aim lower than 40°
Step-by-step explanation: