What are transferred in an oxidation-reduction reaction?

atoms***
electrons
ions
protons

Nope.

Then would it be electrons?

In an oxidation-reduction (redox) reaction, electrons are transferred.

Explanation:
In a redox reaction, oxidation and reduction occur simultaneously. Oxidation is the loss of electrons from a substance, while reduction is the gain of electrons by a substance. During this process, electrons are transferred from one atom to another.

To determine what is being transferred in a redox reaction, you can keep track of the changes in oxidation numbers of the elements involved. The element or compound that gets oxidized will have an increase in its oxidation number, indicating the loss of electrons. Conversely, the element or compound that gets reduced will have a decrease in its oxidation number, indicating the gain of electrons.

Remember, in a balanced redox equation, the total number of electrons lost must be equal to the total number of electrons gained.