Answer:
b. Li
Explanation:
A reducing agent is a substance in a redox reaction that reduces another substance, but gets oxidized itself. It becomes oxidized by donating electrons to another substance, which accepts it and gets reduced.
According to the given equation in this question:
Cu2+ + 2 Li → Cu + 2Li+
In the above equation, lithium (Li) which was at an oxidation state of O in the reactant side has become oxidized in the product side i.e. Li → Li+. This means that lithium is the reducing agent.
