Consider the following statements as regards BPSK and QPSK:

1. In BPSK we deal individually with each bit of duration T_b
2. In QPSK we lump two bits to form a symbol
3. In both BPSK and QPSK signal changes occur at bit rate
4. In QPSK the symbol can have any one of four possible values

Which of the above statements are correct?