Answer:
(a) Iron is being oxidized.
(d) Sulfur is being reduced.
Step-by-step explanation:
Let's consider the following redox reaction.
8 Fe(s) + S₈(s) → 8 FeS(s)
Iron is being oxidized according to the following oxidation half-reaction:
Fe(s) → Fe²⁺(s) + 2 e⁻
Sulfur is being reduced according to the following reduction half-reaction:
S₈(s) + 16 e⁻ → 8 S²⁻(s)