Mastering Java: The Ultimate Quiz for 'Thinking in Java' 2026 - Free Java Programming Practice Questions and Study Guide

Generics is the correct answer as it allows for specifying the type in a class. Inheritance, polymorphism, and encapsulation are all fundamental concepts in Java, but they do not involve explicitly specifying the type in a class. Inheritance allows for one class to inherit properties and methods from a parent class, polymorphism allows for objects to take on different forms and behaviors, and encapsulation is the practice of hiding data within a class and only allowing access to it through methods.