在如下源代码文件 Test . java 中 , 哪个是正确的类定义 ?
A.
public class test { public int x = 0; public test(int x) { this.x = x; } }
B.
B 、 public class Test { public int x=0; public Test(int x) { this.x = x; } }
C.
public class Test extends T1, T2 { public int x = 0; public Test (int x) {this.x = x;} }
D.
protected class Test extends T2 { public int x=0; public int Test(int x) {this.x=x;} }