question_answer

While bathing in a pond Robert observed that he could not breathe under water. He found the following conclusions for this reason. Choose the correct one.

A)  He has some breathing problem

B)  Sufficient oxygen is not dissolved in the water

C)  Due to excess concentration of carbon dioxide in the water

D)  We are a terrestrial animal so our respiratory system has developed to suit the terrestrial environment rather than aquatic environment

E)  None of these