At 17° temperature and fixed volume, heat of reaction of the following reaction: C_(s) + \( \frac{1}{2} O_{2} \left ( g \right ) \) = CO_(g) is found as -122.55 KJ. What is the heat of reaction at fixed pressure?

A -122.55 KJ

B -1221.989 KJ

C -121.344 KJ