Which statement is true？（）

• A、Compilation fails.
• B、An exception is thrown at runtime.
• C、Synchronizing the run（） method would make the class thread-safe.
• D、The data in variable "x" are protected from concurrent access problems.
• E、Declaring the doThings（） method as static would make the class thread-safe.
• F、Wrapping the statements within doThings（） in a synchronized（new Object（））{} block would make the class thread-safe.