Select all the statements below which are TRUE: If L is a regular language, then L is context-free. If G is a context-free grammar, then the left-most derivation is obtained if the right-most variable is replaced at each step of the derivation. Let G = (V, T, S, P) be a context-free grammar. Then a partial derivation tree of G always has the root labeled S. The grammar below is an s-grammar: S rightarrow aS | bA | lambda A rightarrow aA | bB B rightarrow b Let G be a context-free grammar. If a string w elementof L(G) is the yield of two different derivation trees of G, then G is ambiguous. Consider the grammar below: S rightarrow AaAa | Bb A rightarrow Aaa | lambda B rightarrow b If we remove the lambda - production, then we get the following equivalent grammar: S rightarrow AaAa | aAa | Aaa | Bb |aa A rightarrow Aaa | aa B rightarrow b