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: ENT
Not self retaining hand held retractor (s) is/are: 
Select and explain. 
A. Mollison's mastoid retractor, B. Jansen's mastoid retractor, C. Lempe's endaural retractor, D. Davis Retractor
D: Davis Retractor
Answer: D: Davis Retractor 
Explanation: Answer- D. Davis RetractorThese retractors do not need an assistant to hold them in place.It hold tissue apa and lock it in place.Hand held retractor-Hohmann RetractorLahey RetractorSenn RetractorBlair (Rollet) RetractorRigid RakeFlexible RakeRagnell RetractorLinde-Ragnell RetractorDavis Retractor