The following code:
stmt → if expr then stmt else stmt
| if expr then stmt
suffers from:

Correct option is A

The given grammar is ambiguous because a string like ‘if expr then if expr then stmt else stmt’ can have more than one parse tree. This ambiguity makes it unclear whether the else clause is associated with the first or second if statement. Ambiguity in grammars leads to difficulties in parsing and interpreting code correctly, which is why it is critical to resolve or avoid ambiguous grammars in language design.