Valve of Rosenmuller is located at: (A) Cystic duct, (B) Opening of nasolacrimal duct, (C) Junction of lacrimal sac and canaliculus, (D) Ampulla of vater
Answer is C. A fold of mucous membrane found at the junction between the common canaliculus and the lacrimal sac. It is not strictly a valve because fluids can be blown back to emerge at the puncta. It is not always fully developed. ref -medscape.com