Quadrinuckeate cyst is itz infectous stage and it is cld magna i guess...

Transmission of Entamoeba histolytica
Entamoeba histolytica is a parasitic protozoan that causes amoebic dysentery and amoebic liver abscess in humans. The transmission of this parasite occurs through the ingestion of its cyst form, which is resistant to environmental conditions and can survive outside the host. There are several ways in which Entamoeba histolytica can be transmitted:

1. Contaminated Food and Water: The most common mode of transmission is through the ingestion of contaminated food and water. The cysts of Entamoeba histolytica can be present in fecally contaminated water sources or on unwashed fruits and vegetables. When these cysts are ingested, they can release the infective form of the parasite (trophozoites) in the intestines.

2. Fecal-Oral Route: Another important mode of transmission is the direct transfer of cysts from the feces of an infected individual to the mouth of another person. This can occur through poor hygiene practices, such as not washing hands properly after using the toilet. The cysts can then be ingested and cause infection.

3. Sexual Transmission: In rare cases, sexual transmission of Entamoeba histolytica can occur. The parasite can be present in the rectal area and can be transferred during anal-oral sexual practices. This mode of transmission is more common among men who have sex with men.

4. Contaminated Surfaces: Entamoeba histolytica cysts can survive on surfaces for a certain period of time. If these surfaces are touched and then the hands are brought to the mouth, the cysts can be ingested and cause infection.

5. Mother-to-Child Transmission: Vertical transmission from an infected mother to her newborn baby can occur during childbirth. This is considered a rare mode of transmission.

Conclusion:
The correct answer to the question is option 'A' - Entamoeba histolytica is transmitted from host to host by means of quadrinucleate cysts. These cysts are the environmentally resistant form of the parasite and can survive in the external environment until they are ingested by a susceptible host. Once inside the host, the cysts can release the infective trophozoites, which can cause disease. It is important to practice good hygiene, such as proper handwashing, and to ensure the safety of food and water sources to prevent the transmission of Entamoeba histolytica.