In your production database there is a job， CALC_STAT， which has been scheduled to run every Friday at 5：00 p.m. CALC_STAT updates the optimizer statistics for the objects owned by the APPS schema. You want the task to be generic， thereby allowing users to modify the attributes of the task at run time without affecting the original task. Which component of Oracle Scheduler must you define to achieve this？（）

A. Window
B. Program
C. Job class
D. Window grou