In Java, top-level classes (i.e., not inner classes) can only have:
public → accessible from anywhere.
default (no modifier) → accessible only within the same package.
private and protected cannot be used with a top-level class.
final means the class cannot be inherited, but it doesn’t restrict access across packages.
(a) private → ❌ Not allowed for a top-level class.
(b) protected → ❌ Not allowed for a top-level class (only applies to members).
(c) final → ❌ Only prevents subclassing, not accessibility.
(d) don’t use any keyword at all (make it default) → ✅ Correct!
A default (package-private) class is accessible only within the same package.
Classes outside the package cannot access it.
✅ Answer: (d) don’t use any keyword at all (make it default)