Describe, compare, and contrast primitives (integer, floating point, boolean, and character), enumeration types, and objects. Describe, compare, and contrast concrete classes, abstract classes, and interfaces, and how inheritance applies to them. Describe, compare, and contrast class compositions, and associations (including multiplicity: (one-to-one, one-to-many, and many-to-many), and association navigation. Describe information hiding (using private attributes and methods), encapsulation, and exposing object functionality using public methods; and describe the JavaBeans conventions for setter and getter methods. Describe polymorphism as it applies to classes and interfaces, and describe and apply the "program to an interface" principle
SCJA Exam Objectives taken from http://www.sun.com/training/catalog/courses/CX-310-019.xml

public class PropertyCheck {
    private int limit;
}

a. and d. are correct.

b. and c. is correct.

c. and d. are correct.

b. is correct.

a. is correct.