Answer: Option (c) is the correct answer.
Step-by-step explanation:
A compound is defined as the substance in which different elements are chemically combine together in a fixed ratio by mass.
For example,
and KOH are both compounds in the given reaction equation.
Here, in
the atoms are present in 2:1 ratio and in KOH compound the atoms are present in 1:1 ratio.
A compound can be divided into its constituent or simpler substances.
Thus, we can conclude that in the given reaction only
is the compound which has an element ratio of 2:1.