For a given steam temperature of $$850^\circ$$ C and vacuum of 0.1 kg/$$cm^2$$ absolute, the Rankine cycle efficiency will be maximum when steam pressure is:

A

100 $$kg/cm^2$$

B

200 $$kg/cm^2$$

C

Critical pressure (225.4 $$kg/cm^2$$)

D

350 $$kg/cm^2$$