The correct option is B Human liver
The exoerythrocytic stage is the developmental stage of the malaria parasite (Plasmodium) in liver parenchyma cells of the vertebrate host before erythrocytes are invaded. sporozoites are picked up by the liver cells. This changes into merozoites which are released into the bloodstream to invade the RBC. Some of the merozoites turn into gametocyte and help in continuation of the cycle.
Therefore, the correct answer is option B.