Which of the following statements start a new thread?

a)

Thread t1 = new Thread(()-> System.out.println("I want to run ..."));
t1.start();

b)

Thread t2 = new Thread(new Runnable() {
  @Override
  public void run() {
    System.out.println("I want to run ...");
  }
});
t2.start();

c)

Thread t3 = new Thread (()->System.out.println("I want to run ..."));
t3.run();      

d)

Runnable t4 = () -> System.out.println("I want to run");
t4.start();