Which of the following are C2 epimers ?
a) D- mannose
b) D - galactose
c) D- glucose
d) D - allose
a,b
b,c
a,c
c,d
As we have learnt,
Epimers are isomers that differ in configuration at one of the asymmetric / chiral centre.
Glucose and Mannose are C-2 epimers as represented below
D - mannose D-glucose
Note: Other epimers of Glucose include Allose (C-3) and Galactose (C-4)
Hence, the correct answer is Option (3)