设有如下代码: class Base { } public class MyCast extends Base { static boolean b1 = false; static int i = -1; static double d = 10.1; public static void main(String argv[]){ MyCast m = new MyCast(); Base b = new Base(); //Here } } 则在 //Here处插入哪项的代码将不出现编译和运行错误? A. b = m; B. m = b; C. d = i; D. b1 = i;