for proving A true we can take the language $L= \left\{a^n b^m c^m \right\}$ U $\left\{a^n b^n c^m \right\}| m,n>0$ then for that you can write only one possible grammer $S->S1|S2;$ $S1->AB;$ $A->aA|a;$ $B->bBc|bc$

and for $S2->CD;$ $C-> aCb|ab;$ $D->cD|c$

then for string $'aabbcc'$ we have two parse tree so ambiguous thats why here language is ambiguous bcz the defination of inherit ambigous for a language L is if we can form L using many grammer and each grammer must be ambiguous then we said L is inheritly ambiguous.

definition of inherit ambagious for a language L is if we can form L using many gammer and each gammer must be ambiguous then we said L is inheritly ambiguous .

Q 1: so for every CFL if Gammer is ambagious then All the Gammer(if possible) generating that CFL are ambiguous and we can't convert ambiguous gammer to unambiguous gammer.is this correct?

Q 2:Can we convert all every ambiguous gammer to equivalent unambiguous gammer?

-->I think checking whether gammer is ambiguous or not is undecidable so converting will be undecidable so ans will be No but I need your confirmation