When will the null object be garbage collected. : Questions « Java Source And Data Type « SCJP

1. SCJP
2. Java Source And Data Type
3. Questions

public class MainClass{

   public MainClass(){
        StringBuffer sbuf = new StringBuffer();
        sbuf = null;
        System.gc();

        //...
   }
}


A. After 'sbuf = null', the sbuf is garbage collected.
B. After 'System.gc()', the sbuf is garbage collected.
C. After 'sbuf = null', the sbuf is eligible for garbage collection.
D. After 'System.gc()', the sbuf is eligible for garbage collection.