Which two statements are true regarding subqueries? (Choose two.) 

Answer options:

A. A subquery can appear on either side of a comparison operator.
B. Only two subqueries can be placed at one level.
C. A subquery can retrieve zero or more rows.
D. A subquery can be used only in SQL query statements.
E. There is no limit on the number of subquery levels in the WHERE clause of a SELECT statement.

AC