在下列源代码文件Test.java中,哪个选项是正确的类定义? ( )
A.
public class test { public int x=0; public test(int x) { this.x=x; } }
B.
public class Test { public int x=0; public Test(int x) { this.x=x; } }
C.
public class Test extends Ti,T2 { public int x=0; public Test(int x) { this.x=x; } }
D.
protected class Test extends T2 { public int x=0; public Test(int x) { this.x=x; } }