单项选择题

A.Move the loop code into the constructor of the service class from the OnStart method.
B.Drag a timer component onto the design surface of the service. Move the calls to the long-running procedure from the OnStart method into the Tick event procedure of the timer, set the Enabled property of the timer to True, and call the Start method of the timer in the OnStart method.
C.Add a class-level System.Timers.Timer variable to the service class code. Move the call to the DoWork method into the Elapsed event procedure of the timer, set the Enabled property of the timer to True, and call the Start method of the timer in the OnStart method.
D.Move the loop code from the OnStart method into the DoWork method.