Which statement is true？（）
- ACompilation fails.
- BAn exception is thrown at runtime.
- CSynchronizing the run（） method would make the class thread-safe.
- DThe data in variable "x" are protected from concurrent access problems.
- EDeclaring the doThings（） method as static would make the class thread-safe.
- FWrapping the statements within doThings（） in a synchronized（new Object（））{} block would make the class thread-safe.