The correct answer is Option (3) as the correct route of milk ejection via mammary glands in human is: Mammary alveolus ⟶ Mammary tubule ⟶ Mammary duct ⟶ Mammary ampulla ⟶ Lactiferous duct In the question, the given structures are represented as:- C⟶E⟶A⟶D⟶B (given in option 3 ) The other option i.e., (1), (2) and (4) are incorrect as they represent the wrong pathway.