Which three are true about scalar subquery expressions? (Choose three.)

[answerhappygod]

Which three are true about scalar subquery expressions? (Choose three.)

A. They can be nested.
B. They cannot be used in the VALUES clause of an INSERT statement.
C. A scalar subquery expression that returns zero rows evaluates to zero.
D. They can be used as default values for columns in a CREATE TABLE statement. E. A scalar subquery expression that returns zero rows evaluates to NULL. F. They cannot be used in GROUP BY clauses.