Combination which gives False on exactly two of p,q,r are true.
Option A --- (P,Q,R) = (F,T,T)
Option C--- (P,Q,R) = (T,F,T)
Option D--- (P,Q,R) = (T,T,F) or (T,F,T) or (F,T,T)
Now, option B these combination give true..
Option B --- (P,Q,R) = (T,T,F) or (T,F,T) or (F,T,T)