Given: public class CheckIt { public static void main (String[] args) { if (doCheck()) { System.out.print("square "); } System.out.print("..."); } public static int doCheck() { return 0; } }

A is incorrect because the code will not compile due to a type mismatch, preventing any runtime output.

B is incorrect for the same reason as A; the code will not compile, so no output is produced.

C is correct because Java's 'if' statement explicitly requires a boolean expression within its parentheses. The 'doCheck()' method returns an 'int' (specifically 0), which Java does not implicitly convert to a boolean value. This fundamental type mismatch is detected by the compiler, preventing the code from running.

D is incorrect because the error is a compile-time type mismatch, not an exception thrown during runtime execution.