What is the type of the value returned by the method isEmpty?

Which of the following is true about all doubly linked lists?

a) each node references both its predecessor and its successor b) the precede reference of the last node has the value null c) the last node references the first node d) the precede reference of the first node references the last node

Answer the following statements true (T) or false (F)

1. The top-down design process is sometimes referred to as stepwise refinement. 2. The scope of a variable is the segment of the program in which the variable can be accessed. 3. A module can have two or more variables with the same name because they are within the same scope. 4. The arguments in a module call and the parameters listed in the module header must be of compatible data types. 5. The scope of the parameter variables is the entire program and they are visible to any statement in the program.