This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Parasitology, Subject name: Microbiology
Ascariasis causes: 
Select and explain. 
A. Appendicitis, B. Intestinal obstruction, C. Bile duct obstruction, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Ans. (d)(Ref: Parasitology-Protozoology and Helminthology by K.D. Chatterjee, 13th edition)The worm inhabits the upper part of the small intestine. Pathogenic effect are:Spoliative action: robbing the host of its nutrition.Toxic action: may give rise to typhoid like fever, responsible for allergic reactions urticarial, oedema of the face, conjunctivitis and irritation of the upper respiratory tract.Mechanical effects-can cause intussusception, can penetrate through the ulcers of the alimentary canal, intestinal obstruction.Ectopic Ascariasis.