Evaluate the following statement：   Which statement is true regarding the evaluation of rows returned by the subquery in the INSERT statement？（）

• A、 They are evaluated by all the three WHEN clauses regardless of the results of the evaluation of any other WHEN clause.
• B、 They are evaluated by the first WHEN clause. If the condition is true， then the row would be evaluated by the subsequent WHEN clauses.
• C、 They are evaluated by the first WHEN clause. If the condition is false， then the row would be evaluated by the subsequent WHEN clauses.
• D、 The INSERT statement would give an error because the ELSE clause is not present for support in case none of the WHEN clauses are true.