Sybex
Java OCP 8 Study Guide Small Typo Chapter 3 page 168
question 18
A. A a1 = new A();
B. A a2 = new B();
C. A a3 = new C();
D. C c1 = new A();
E. C c2 = new B();
F. C c1 = new C();
Option F c1 should be c3 for consistency.
a1 a2 a3 c1 c2 "c1" should be a1 a2 a3 c1 c2 "c3"
it is a small typo