In one of your online transaction processing （OLTP） applications， most users frequently modify the values， including the key values， of the application tables. Some users generate application reports by using multiple application tables. What is the best table structure that you can use to gain optimal performance？（）

A. Heap table
B. Object table
C. External table
D. Clustered table
E. Global temporary table
F. Index-organized table （IOT）