Answer:
The answer to your question is letter d. Synthesis
Step-by-step explanation:
a. In a decomposition reaction, one single reactant splits out and forms 2 or more products.
b. In a single replacement reaction, a single atom replaces the cation of a molecule.
c. In a combustion reaction, an organic molecule reacts with oxygen to form carbon dioxide and water.
d. In a synthesis reaction, two reactants or more reactants combine to form one single product.
e. In a double replacement reaction, two molecules interchange cations and anions.