The given figure shows the nephridial system of earthworm and answer the question.

Select the option which shows the correct identification and the function of the structure marked as X.

Correct Answer : D.

Blood glands are present on the 4th, 5th and 6th segments. They produce blood cells and haemoglobin which is dissolved in blood plasma. Blood cells are phagocytic in nature. Lateral hearts are present in 7th and 9th segments and connects dorsal blood vessel with ventral blood vessel. The Nephridia is an organ which occurs in pairs and performs a function similar to the vertebrate kidney. Nephridia remove metabolic wastes from an animal's body.