Which concept of grammar is used in the compiler?a) Lexical analysis b) Parser c) Code generation d) Code optimization

The concept of grammar is used in both a) Lexical analysis and b) Parser stages of a compiler.

a) Lexical analysis: This is the first phase of a compiler. It takes the source code as input and converts it into tokens. The grammar here is used to identify and categorize the tokens based on predefined rules.

b) Parser: This is the second phase of a compiler. It takes the tokens generated by the lexical analyzer and groups them into grammatical sequences that are used by the compiler to produce the intermediate code. The grammar rules are used here to verify if the expressions formed by the tokens follow the syntax of the language.

c) Code generation and d) Code optimization: These stages of the compiler do not directly use the concept of grammar. Code generation is the process of converting the intermediate code into the target language, and code optimization is the process of improving the intermediate code so that the output runs more efficiently.