I have a tedious if statement to be made. What is an easier way of doing it.

If B2 is a or b or c or d or e or f, then a2 is XX
if B2 is g or h or i or j, then a2 is YY
if b2 is k or l or m or n or p, then a2 is ZZ
if b2 is q or r or s or t then a2 is ab
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Is there a way or writing this in a if/or statement??