Correct Answer: AUsing Contact roles on the Opportunity object is the best solution because it allows sales executives to associate decision makers and influencers directly with specific opportunities. This method enables the sales team to track and manage the roles of various contacts in relation to each opportunity, which is crucial for prioritizing interactions and furthering business relationships. A multi-select picklist field or a contact lookup field would not provide the same level of detail and tracking, while a junction object would add unnecessary complexity without additional benefits.