###Rationale: Ans. is 'b' i.e., 3000 cells/mm2 The cell density of corneal endothelium is around 3000 cells/mm2 in young adults, which decreases with the advancing age.

###Answer: OPTION B IS CORRECT.
###Question: Density of cells in adult corneal endothelium ?
###Options:
A. 2000 cells/mm2
B. 3000 cells/mm2
C. 4000 cells/mm2
D. 5000 cells/mm2
