The correct answer is C. Select query.

A select query is a type of database query that retrieves data from a database. It is the most common type of query and is used to select specific data from a table or view.

A search query is a type of query that is used to find information on the internet. It is used to search for websites, images, videos, and other types of content.

A cross tab query is a type of query that is used to summarize data from multiple tables. It is used to create a table that shows the totals of a particular field for each group of records.

An update query is a type of query that is used to change data in a database. It is used to update the values of fields in a table or view.

In the given question, the user wants to know the average salary of the employees. This can be calculated by using a select query. The select query will retrieve the salary data from the employee table and calculate the average.

The following is an example of a select query that can be used to answer the question:

sql SELECT AVG(salary) AS average_salary FROM employees;

This query will return the average salary of all employees in the employees table.