Which of the following statements is incorrect about the frog?
(i) Eyes are bulged out and covered by a nictitating membrane that protects them while in water
(ii) On either side of the eyes a membranous tympanum (ear) receives sound signals
(iii) The hind limbs end in four digits and they are larger and muscular than fore limbs that end in five digits
(iv) Feet have webbed digits that help in swimming
(v) Frogs exhibit sexual dimorphism