Which of the following half reaction equations represent the reaction at the cathode

Consider the following diagram and use it to answer the question below

A. A³⁺_(aq) + 3e⁻ → A_(s)
B. B²⁺_(aq)+2e− → B_(s)
C. A_(s) → 3⁺_(aq)+3e⁻
D. B_(s) → B²⁺_(aq) + 2e

Correct Answer:

Option B = B²⁺_(aq)+2e− → B_(s)