Answer:
E
Explanation:
A combination reaction is one in which two elements or two compounds react to give a new single compound
Hence, what we are expecting on the reactant side is only a single product and not a mixture of products
For the first reaction, we had two elements giving a single product
For the second reaction, we had same
For the third, we had same
For the fourth, we had two compounds reacting to give a singe new product
While in the last, we had two different products which means it does not follow the definition of a combination reaction and that makes it our answer