Which of the following is not a symptom of a disease caused by E. his…

The correct answer is Option (4) → Nasal discharge

Entamoeba histolytica is a protozoan parasite of the large intestine of humans. It causes amoebiasis (amoebic dysentery). Since it lives in the gut, its symptoms are those of the gut. Houseflies carry the parasite from faeces to food, and contaminated food and water spread it.

Option (1) Presence of excess mucus and blood clots in stools — A symptom of amoebiasis. Stools with excess mucous and blood clots are a typical sign of amoebic dysentery.

Option (2) Persistent constipation — A symptom of amoebiasis. Constipation is one of the symptoms the book lists for this disease.

Option (3) Abdominal pain and cramps — A symptom of amoebiasis. Abdominal pain and cramps come from the parasite in the large intestine.

Option (4) Nasal discharge — Not a symptom of amoebiasis. Nasal discharge is a sign of an infection of the nose and respiratory passage, such as the common cold caused by rhinoviruses. The amoeba does not infect the nose.

NCERT Extract:
Common Diseases in Humans – “Entamoeba histolytica is a protozoan parasite in the large intestine of human which causes amoebiasis (amoebic dysentery). Symptoms of this disease include constipation, abdominal pain and cramps, stools with excess mucous and blood clots. Houseflies act as mechanical carriers and serve to transmit the parasite from faeces of infected person to food and food products, thereby contaminating them.”
Common Diseases in Humans – “… They infect the nose and respiratory passage but not the lungs. The common cold is characterised by nasal congestion and discharge, sore throat, hoarseness, cough, headache, tiredness, etc., which usually last for 3-7 days.”