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
Calabar swelling is produced by- 
Select and explain. 
A. Onchocerca volvulus, B. Loa loa, C. Brugia malayi, D. Wuchereria bancrofti
B: Loa loa
Answer: B: Loa loa 
Explanation: Calabar Swelling: Localized angioedema and erythema usually on the extremities, characterized by fugitive, swollen lumps of subcutaneous tissue caused by a parasitic filarial worm (Loa loa) endemic to Central and West Africa.
The swollen areas migrate with the worm through the body at a speed of about 1 cm per minute and may become as large as a small egg.