During the trophozoite stage of parasite growth there are many changes to both parasite and the red cell it is contained in. All species dorm malarial pigment (haemozoin) as they develop as it is essential to their safe development.
Explanation of correct answer (click "Expand")
Short answer taken from section "Malaria Biology - Malaria Pigment" (see the section for full details and links).
During their development malarial parasites metabolise the haemoglobin within erythrocytes to support their growth. Infected red cells at late stages of parasite development may have no visible haemoglobin. As part of that process the parasite must "detoxify" the iron component of the haem element. This process creates a detoxified iron containing protein "haemozoin" which is visible as pigment - as you might expect this is most visible at late stages of parasite development when haemoglobin is fully metabolised. When schizonts rupture to release their daughter parasites, the pigment is also released and is takn up by phagocytes.