A gas undergoes a process in which state variable changes from $\left( 1 \mathrm {~atm} , 60 \mathrm { ml } , 27 ^ { \circ } \mathrm { C } \right)$ to $\left( \mathrm { P } \mathrm { atm } , 30 \mathrm { ml } , 77 ^ { \circ } \mathrm { C } \right)$ then P is
(A) $\frac { 7 } { 3 } \mathrm {~atm}$
(B) 2 atm
(C) 5 atm
(D) 7 atm