Which is the most likely to be reduced A. Fe2 plus B. Ni2 plus C. Cu2 plus D. Zn2 plus?

The most likely to be reduced among the options given is Cu²⁺ (C). This is due to its higher standard reduction potential compared to the other cations, which makes it more favorable to gain electrons and be reduced. Fe²⁺ (A) and Ni²⁺ (B) have lower reduction potentials, while Zn²⁺ (D) is less likely to be reduced because it is more readily oxidized.