This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdomen & Pelvis, Subject name: Anatomy
Lower l/3rd of anal canal is derived from- 
Select and explain. 
A. Proctodaeum, B. Cloaca, C. Urogenital Sinus, D. Midgut
B: Cloaca
Answer: B: Cloaca 
Explanation: Ans. is 'b' i.e., Proctodaeum * 'The lower third of the anal canal is an ectodermal derivative and is derived from the proctodaeum.'* Part of anal canal above pectinate line develops from dorsal part of endodermal cloaca (primitive rectum) and part of anal canal below pectinate line develops from ectodermal proctodeum.