The correct option is C 4P
The ideal gas equation states that,
PV=nRT
So, we can conclude from the data given in the question that,
P∝T (As V is constant)
Hence, P1P2=T1T2 ........(1)
Given, T1=300 K,T2=1200 K,P1=P
∴ From (1), we can write that
P2=P1 T2T1
⇒P2=P×1200300
⇒P2=4P
Thus, option (c) is the correct answer.