Given:


Which regular expression, inserted at line 12, correctly splits test into "Test A", "Test B", and "Test C"?（）

A.It is true that j==i.
B.It is false that j==i.
C.An exception is thrown at runtime.
D.Compilation fails because of an error in line 13.

A.Compilation fails.
B.The file system has a new empty directory named dir.
C.The file system has a new empty directory named newDir.
D.The file system has a directory named dir, containing a file f1.txt.
E.The file system has a directory named newDir, containing a file f1.txt.

A.sb1.append("abc"); s1.append("abc");
B.sb1.append("abc"); s1.concat("abc");
C.sb1.concat("abc"); s1.append("abc");
D.sb1.concat("abc"); s1.concat("abc");
E.sb1.append("abc"); s1 = s1.concat("abc");
F.sb1.concat("abc"); s1 = s1.concat("abc");
G.sb1.append("abc"); s1 = s1 + s1.concat("abc");
H.sb1.concat("abc"); s1 = s1 + s1.concat("abc");