This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thromboembolism and Fat Embolism Syndrome, Subject name: Medicine
Lovibond angle is: 
Select and explain. 
A. Angle between the iris and cornea, B. Angle between the long axis of the forearm and the long axis of upper arm, C. Angle between nail bed and proximal nail fold, D. Angle between manubrium sternum and body of sternum
C: Angle between nail bed and proximal nail fold
Answer: C: Angle between nail bed and proximal nail fold 
Explanation: Lovibond angle or Hyponychial angle - Angle between nail bed and proximal nail fold - Normally around 1600. - It is >1800 in digital clubbing. It is described as a 'profile sign'