Which of the following are the four main types of chemical reactions?

The four main types of chemical reactions are indeed best categorized as synthesis, decomposition, single displacement, and double displacement.

Synthesis reactions involve two or more reactants combining to form a single product. Decomposition reactions are characterized by a single reactant breaking down into two or more simpler products. Single displacement reactions occur when an element displaces another in a compound, while double displacement reactions involve the exchange of ions between two compounds, resulting in the formation of two new compounds.

These categories cover a wide range of chemical processes and form the foundation from which more complex reactions can be understood. Each type corresponds to specific patterns of bonding and energy changes that are essential for predicting the outcomes of reactions in various contexts.

While other options mention various types of reactions, they either include special cases or broader classifications that are not all primary types of reactions in the same way as synthesis, decomposition, single displacement, and double displacement are.