When three or more AND and OR conditions are combined, it is easier to use the SQL keyword(s):

Option A: LIKE only. - The LIKE keyword is used for pattern matching with wildcard characters in SQL, not for combining multiple conditions with AND and OR.
Option B: IN only. - The IN keyword is used to specify multiple values in a WHERE clause, but it is not specifically used for combining multiple conditions with AND and OR.
Option C: NOT IN only. - The NOT IN keyword is used to specify exclusion of multiple values in a WHERE clause, but it is not specifically used for combining multiple conditions with AND and OR.
Option D: Both IN and NOT IN. - This option is incorrect as it does not relate to combining multiple conditions with AND and OR.
Conclusion:
When combining three or more AND and OR conditions in SQL, it is easier to use parentheses to group the conditions logically. There is no specific keyword like IN or NOT IN that simplifies this process. Therefore, the correct answer is None of the above.