This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Ascaris lumbricoides causes deficiency of: 
Select and explain. 
A. Iron, B. Vitamin B 12, C. Folic acid, D. Vitamin A
D: Vitamin A
Answer: D: Vitamin A 
Explanation: Vitamin A