According to which one of the following laws it is indicated that when two or more gases react with one another, their volumes bear a simple ratio?

The law indicating that when gases react, their volumes bear a simple ratio to one another is the Law of Combining Volumes, also known as Gay-Lussac's Law of Gaseous Volumes [t1][t2]. Formulated by Joseph Louis Gay-Lussac in 1808, it states that when gases react at constant temperature and pressure, the volumes of the reacting gases and their gaseous products are in simple whole-number ratios [t3][t4]. For example, the reaction of two volumes of hydrogen with one volume of oxygen yields two volumes of water vapor, demonstrating a 2:1:2 ratio [t3]. This law is distinct from the Law of Multiple Proportions, which relates to the masses of elements in different compounds [t3][t4], and the Law of Reciprocal Proportions, which concerns the mass ratios of two elements combining with a fixed mass of a third [t2][t4]. The Law of Mass Action relates to reaction rates and chemical equilibrium rather than volumetric ratios.