Read the following statements carefully
(i) In fishes, the heart pumps out deoxygenated blood which is oxygenated by the gills and supplied to the body part from where deoxygenated blood is returned to the heart
(ii) The openings of the right and the left ventricles into pulmonary artery and aorta respectively are provided with the mitral valves
(iii) The nodal musculature has the ability to generate action potential without any external stimuli, i,e., it is autoexcitable
(iv) The T-wave of ECG represent depolarisation of the ventricles.
Which of the above two statements are incorrect ?