The operators that are used when a subquery returns multiple rows to be evaluated in comparison to the outer query are . . . . . . . .

Answer: Option A

This question is about how to handle situations where a subquery (a query nested inside another query) returns multiple results.
Let's break it down:
* Subqueries: These are smaller queries within larger queries. Imagine a query looking for all customers who bought a specific product. The subquery might be to find the IDs of all customers who bought that product.
* Multiple Rows: When a subquery returns multiple results, we need special operators to compare these results with the outer query.

Now, let's look at the options:
A: IN and NOT IN: These are perfect for dealing with multiple rows. They let you check if a value in the outer query exists (or doesn't exist) in the list of values returned by the subquery.
B: EXISTS and NOT EXISTS: These check if a subquery returns any rows at all. They don't compare individual values.
C: OUTER JOIN and INNER JOIN: These combine data from different tables, but they are not specifically designed for handling subqueries with multiple rows.
D: LEFT JOIN and RIGHT JOIN: These are also used for combining tables, and aren't the primary tools for working with subqueries returning multiple results.

Therefore, the answer is Option A: IN and NOT IN.
IN checks if a value is present in the list returned by the subquery, and NOT IN checks if a value is *not* present in that list.