When the pressure drop across a converging–diverging nozzle is different from the design value for isentropic flow, which of the following is possible?
(A) There is one normal shock in the converging part and one normal shock in the diverging part
(B) There is only one normal shock in the converging part and none in the diverging part
(C) There is only one normal shock in the diverging part and none in the converging part
(D) There are two or more normal shocks, depending on the pressure drop, in the diverging part and none in the converging part