Explanation:

- Intervene: This means to step in or get involved in a situation to influence the outcome. It's often used in contexts where mediation or interference is needed to resolve an issue.

- Option 1: Embody: To represent an idea or quality in a tangible form. Not a synonym for intervene.

- Option 2: Combine: To join or merge different elements together. Lacks the element of stepping into a situation to influence it.

- Option 3: Coalesce: To unite or come together to form a whole. Not related to intervening in a situation.

- Option 4: Arbitrate: This involves mediating or settling a dispute between parties, which closely aligns with the idea of intervene.