Infection of Ascaris usually occurs by Eating imperfectly cooked port, Drinking water containing eggs of Ascaris, Tse-tse fly, Mosquito bite

Infection of Ascaris (one species of roundworms) results in ascariasis. Ascariasis occurs when the eggs that have been excreted in human feces and ingestion of drinking water or consuming uncooked food contaminated by soil containing eggs of Ascaris.Thus, the correct answer is option B (Drinking water containing eggs of Ascaris).