The correct option is A CO gas will be released
Solubility of gases in liquids decreases on increasing the temperature. As we increase the temperature of a solution, the quantity of gas dissolved will be reduced. This is because the kinetic energy of the dissolved gas particles increase with increase in temperature. In turn, some of the gas particles will escape out of the solution.
In this case, CO was already dissolved till saturation. On increasing the temperature, the kinetic energy of CO molecules increases. Thus, they will escape out of the solution.