Which statement instructs a program to run the garbage collector?

A) System.clearGarbage() ;
B) System.flushGarbage() ;
C) System.out() ;
D) System.gc() ;

The correct statement to run the garbage collector in Java is System.gc(). This statement suggests to the Java Virtual Machine (JVM) to initiate garbage collection, which will release unused memory from objects that are no longer in use. Option A, System.clearGarbage(), and Option B, System.flushGarbage(), are not valid methods in Java. Option C, System.out(), is just a standard output method that displays text on the console.