For each record, I need to retrieve the maximum of 3 columns.

Example:
ID 1 has column C1= 2, C2=5, C3=1
ID 2 has column C1=6, C2=3, C3=8

I need maximum of C1,C2,C3:
ID 1 gives 5
ID 2 gives 8

Can we do this using SELECT statement?
Thank you all!