I would suggest the answer would be both A and D, mail merge is used to specify different field for different recipients. 
        
                    
             
        
        
        
Option b is correct. When an overridden method is called from within a subclass, it will always refer to the version of that method defined by the subclass.
Subclasses are classes that can be created by adding new functionality to a parent class, such as new object variables or new methods. In terms of automata theory, a subclass expands the state transition table with new rows and states. However, by overriding (changing) existing functionality, the majority of OO programming languages also enable us to derive subclasses from parent classes. When implementing a class, all that is required to be specified is the new or updated functionality thanks to inheritance mechanisms between parent class and subclass.
Lines connected through a circle connect the subclasses HourlyEmployee and SalaryEmployee to the superclass Employee. The circled letter "d" stands for disjointness, which demands that the specification's subclasses be distinct. As a result, an entity can belong to only one of the specification's subclasses. An individual employee can only be paid either hourly wages or a salary; they cannot be paid both. The open sides of the inheritance (arch) symbols face the superclass.
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Classes called child classes or subclasses inherit methods and variables
        
             
        
        
        
Answer:
2. <em>A reference of type A can be treated as a reference of type B</em> - False
Base class or its objects are not related to their derived class (or its objects).
Explanation:
class A {
    int a;
    public A() {
        a = 7;
    } 
}
class B extends A {
    int b;
    public B() {
        b = 8; 
    } 
}
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1. <em>After the constructor for class B executes, the variable a will have the value 7 </em>- True.
When an object of a derived class is declared, the constructor of base class is called before the constructor of derived class (is called).
3. <em>Both variables a and b are instance variables </em>- True.
Classes can have instance, or member, variables and methods.
4.<em> After the constructor for class B executes, the variable b will have the value 8</em> - True.
When object of class B is declared, its constructor was called, which initialized variable b to 8.
 
        
             
        
        
        
Answer:
D
Explanation:
As it's not fair if they all lose there privileges