Composition class; using super or sub?

Let's consider two classes, super and sup extending super:

Class SuperClass{
    int superDataMember;
}

Class SubClass extends SuperClass{
    int subDataMember;
}

I need to have another CompositeClass class that may use super or sub composition depending on some criteria. My question is: Should I use

1. 
   

   An instance of SuperClass inside CompositeClass

   
   
   
   
   • Thus, I can use either SuperClass instance or SubClass instance.
   
   
   • But how will methods accessing subDataMember behave if the accessed instance is of SuperClass?
   
   
   • 
     

     Maybe an instanceOf check may work at the beginning of each method?

     
     

     
     Class CompositeClass {
         private SuperClass sc;
     
         public getSuperDataMember () {// some code}
         public getSubDataMember () {
         if (this.sc instanceOf SubClass)
             // some code
         }
     }
     
     

   
   
   
   


2. 
   

   An instance of SubClass inside CompositeClass

   
   
   
   
   • 
     

     Thus, I will lose the ability to access SuperClass instances!

     
     

     
     Class CompositeClass {
         private SubClass sc;
     
         public getSuperDataMember () {// some code}
         public getSubDataMember () {// some code
         }
     }
     
     

   
   
   
   


3. 
   

   Implement two versions of CompositeClass, the first is SuperCompositeClass with an instance of SuperClass and the second SubCompositeClass that extends the first with an instance of SubClass!