To answer this question, let's examine each DELETE statement and determine if it is valid or not:
A. Delete from employees where employee_id = (select employee_id from employees);
This statement is not valid because it attempts to delete rows from the same table that it is querying (EMPLOYEES).
B. Delete * from employees where employee_id = (select employee_id from new_employees);
This statement is not valid because the "DELETE" keyword should not be followed by an asterisk (*). It should be "DELETE FROM" instead.
C. Delete from employees where employee_id in (select employee_id from new_employees where name = 'Carrey');
This statement is valid. It deletes rows from the EMPLOYEES table where the employee_id is present in the result of the subquery.
D. Delete * from Employees where employee_id in (select employee_id from new_employees where last_name = 'Carrey');
This statement is not valid because, similar to option B, the "DELETE" keyword should not be followed by an asterisk (*). It should be "DELETE FROM" instead.
The correct answer is C. This statement is valid because it uses the correct syntax and deletes rows from the EMPLOYEES table based on a condition specified in the subquery.