Which of the following is a valid Java keyword (reserved word) recognized by the Java compiler?

Introduction / Context:
Java reserves certain words as keywords so they cannot be used as identifiers. Remembering these is important for reading code and avoiding compilation errors.

Given Data / Assumptions:

• The options mix actual keywords with common identifiers or non-Java concepts.
• Java is case-sensitive; keyword case matters.

Concept / Approach:
Keywords include class, interface, native, synchronized, etc. Non-keywords like string (lowercase) or Float (type name in java.lang) are not reserved. Java has no unsigned keyword for primitive declarations.

Step-by-Step Solution:

Verification / Alternative check:
Try using each as an identifier; only non-keywords will compile as variable names.

Why Other Options Are Wrong:
They are either class names or non-existent in Java’s keyword list.

Common Pitfalls:
Confusing class names with keywords; Java keyword set is fixed and case-sensitive.

Final Answer:
interface