Which of the following statement is wrong?

• A. The critical pressure gives the velocity of steam at the throat equal to the velocity of sound.
• B. The flowin the convergent portion of the nozzle is sub-sonic.
• C. The flow in the divergent portion of the nozzle is super-sonic.
• D. To increase the velocity of steam above sonic velocity (super-sonic) by expanding steam below the critical pressure, the divergent portion for the nozzle is not necessary.