Which of the following can be used to start a new task ?

122.

TaskFactory tf = new TaskFactory();
Task t1 = tf.StartNew(MyTask);

Task t2 = Task.Factory.StartNew(TaskMethod);

Task t3 = new Task(TaskMethod);
t3.Start();

All of the above

Calling StartNew is functionally equivalent to creating a Task using one of its constructors and then calling Start to schedule it for execution. However, unless creation and scheduling must be separated, StartNew is the recommended approach for both simplicity and performance.