The correct option is D erythrocytes
The most abundant cell in human body is Erythrocytes (red blood cells) : 4.5 - 5.5 millions per mL. Platelets are 1,40,000 - 4,00,000 per mL. White blood cells are 5,000 - 10,000 per mL. Neutrophils, lymphocytes and basophils are all included in this number.