A 30 year old patient developed high fever of sudden onset. Peripheral blood smear showed crescent shaped gametocytes. Malaria pigment was dark brown in colour. Which of the following malarial parasites is the causative agent?
Plasmodium falciparum is a unicellular protozoan parasite of humans, and the deadliest species of Plasmodium that causes malaria in humans. 
The parasite is transmitted through the bite of a female Anopheles mosquito and causes the disease's most dangerous form, falciparum malaria. 
Unlike those of other Plasmodium species, the gametocytes of P. falciparum are elongated and crescent-shaped, by which they are sometimes identified. 
A mature gametocyte is 8–12 μm long and 3–6 μm wide. 
Haemozoin is a disposal product formed from the digestion of blood by some blood-feeding parasites, the hematophagous organisms such as malaria parasites (Plasmodium spp.). 
In Plasmodium the food vacuole fills with hemozoin crystals, which are about 100-200 nanometres long and each contain about 80,000 heme molecules.
Detoxification through bio-crystallization is distinct from the detoxification process in mammals, where an enzyme called heme oxygenase instead breaks excess heme into biliverdin, iron, and carbon monoxide.

Ref :https://en.wikipedia.org/wiki/Plasmodium_falciparum#:~:text=Plasmodium%20falciparum%20is%20a%20unicellular,most%20dangerous%20form%2C%20falciparum%20malaria
https://en.wikipedia.org/wiki/Hemozoin
Plasmodium vivax
Plasmodium malariae
Plasmodium falciparum
Plasmodium ovale