What is the nature of haemozoin?

The correct answer is Option (3) - Haemozoin is a toxin released from Plasmodium infected cells.

Haemozoin is a toxin released from Plasmodium-infected cells during the malaria infection cycle. When the malaria parasite (Plasmodium species) infects red blood cells, it digests hemoglobin to obtain nutrients. This process results in the formation of haemozoin, a toxic byproduct. Haemozoin accumulates in the infected cells and contributes to the symptoms of malaria, such as fever and chills, during the parasite's life cycle.

The other options are incorrect because:

• Haemozoin is not a precursor of hemoglobin.
• It is not related to Wuchereria or Trichophyton, which are responsible for other infections, not malaria.

Thus, the correct answer is: Haemozoin is a toxin released from Plasmodium-infected cells.