单项选择题 WhichmethodsfromtheStringandStringBufferclassesmodifytheobjectonwhichtheyarecalled？（）

单项选择题 Which is the earliest line in the following code after which the object created on the line marked （0） will be a candidate for being garbage collected， assuming no compiler optimizations are done？ （）  public class Q76a9 {   static String f（） {   String a = "hello"；   String b = "bye"； // （0）   String c = b + "!"； // （1）   String d = b；  b = a； // （2）   d = a； // （3）   return c； // （4）  }   public static void main（String args[]） {   String msg = f（）；   System.out.println（msg）； // （5）   }   }

多项选择题 Which statements can be inserted at the indicated position in the following code to make the program write 1 on the standard output when run？（）  public class Q4a39 {  int a = 1；   int b = 1；   int c = 1；   class Inner {   int a = 2；  int get（） {   int c = 3；   // insert statement here  return c；   }   }  Q4a39（） {   Inner i = new Inner（）；   System.out.println（i.get（））；  }   public static void main（String args[]） {   new Q4a39（）；   }   }