Answer:
d. Decomposition
Explanation:
Reversible changes -
As the name suggests the the changes which can be reversed back to the original compound , is referred to as reversible changes .
All the physical changes are reversible in nature .
For example ,
Melting of ice , as the ice is melted from solid to liquid form , the liquid can again be converted back to solid , by reducing the temperature .
Hence , the changes are reversible in nature .
The species can not be further merged back to get back the original compound , hence is not a reversible change .