During the query processing the syntax of the query is checked bya.Syntax checkerb.Interpreterc.complierd.Parser

The syntax of the query during query processing is checked by a Parser.

Here's a step-by-step explanation:

1. When a query is submitted, it first goes through a process called parsing.

2. The parser checks the syntax of the query to ensure it follows the rules of the language in which the query is written (like SQL, for example).

3. If the syntax is correct, the query moves on to the next stages of processing which include optimization and execution.

4. If the syntax is not correct, the parser will return an error message, and the query will not be executed.

So, the correct answer is d. Parser.

The syntax of the query during query processing is checked by a Parser (option d).

Here's a step-by-step explanation:

1. When a query is submitted, it first goes through a process called parsing.

2. The parser checks the syntax of the query, i.e., it checks if the query is written according to the rules of the language (SQL, for example).

3. If the syntax is correct, the parser generates a parse tree (or syntax tree) of the query. This tree represents the syntactic structure of the query according to the language's grammar.

4. If the syntax is not correct, the parser will return an error message, indicating that the query cannot be executed because it is not correctly written.

So, the correct answer is d. Parser.