Type 4: regular grammarsProductions are of the form X→a or X→aY where X and Y are nonterminals and a is a terminal. That is the left-hand side must be a single nonterminal and the right-hand side can be either a single terminal by itself or with a single nonterminal. These grammars are the most limited in terms of expressive power.

A. 对
B. 错