When executing a SQL workload，you choose to generate execution plans only， without collecting execution statistics.  Which two statements describe the implications of this？（）

• A、 It produces less accurate results of the comparison analysis.
• B、 It automatically calls the SQL Tuning Advisor for recommendations.
• C、 It shortens the time of execution and reduces the impact on system resources.
• D、 Only the changes in the execution plan，and not performance regression，are detected.