给定下面的类定义,选择正确的答案。 1. public class Calculator{ 2. int a = 3; 3. int b = 4; 4. int c = 6; 5. int d = 8; 6. public int cacl(){ 7. return a + b 8. + c + d; 9. } 10. public static void main(String[] args){ 11. Calculator c = new Calculator(); 12. System.out.println(c.cacl()); 13. } 14. }