Common roundworm infecting human beings is
Ascaris lumbricoides is the large roundworm infecting human beings. It is the most common roundworm infecting humans. It is responsible for ascariasis disease. An estimated one-sixth of the human population is infected by Ascaris lumbricoides. The mode of transmission of disease in humans is via the faecal-oral route. Eggs released by adult females are shed in faeces. So, the correct answer is 'Ascaris lumbricoides'.