Answer:
The answer to your question is b. Mg is being oxidized and c. Mg is the
reducing agent.
Step-by-step explanation:
Reduction is the gain of electrons
Oxidation is the loss of electrons
Reducing agent is the element that oxidizes itself and reduces another element.
Oxidizing agent is the element the reduces itself and oxidizes another element.
In this reaction:
Magnesium loses electrons so it is being oxidized and it is the reducing agent.