Task: Question Answering
Input (English): Question: The standard equilibrium constant for a reaction between ideal gases: 
 Options:  <1> It depends on the initial quantities of the reagents. <2> It takes different values ​​if the reaction is carried out at different pressures. <3> It depends on the volume of the vessel in which the reaction is carried out. <4> It only depends on the temperature. <5> It depends on the nature of the gases.
Output (English): 4