Final answer:
Elected boards are most commonly found in member-serving and advocacy organizations where members actively participate in governance and ensure that the organization's direction is aligned with the interests of its constituents.
Step-by-step explanation:
Elected boards are most common in organizations where stakeholders or members have a significant interest in the governance and direction of the organization. Based on the provided information which states that these organizations 'also influence policy making through lobbying and public education', these characteristics align closely with member-serving and advocacy organizations, which includes various non-profits, volunteer groups, civic organizations, and similar entities where members actively participate in governance and policy-making. A board elected by members fulfills the need for democratic representation and ensures that the organization's direction aligns with the interests of its constituents.In comparison to public organizations, which may also have elected boards, member-serving and advocacy organizations often have a more direct role in electing boards because of the close relationship to their members. In the case of companies headed by a CEO, the board of directors is typically selected by shareholders, and in private, for-profit corporate contexts, this might not involve a broad electoral process involving all stakeholders.
Therefore, elected boards are most commonly found in member-serving and advocacy organizations (option B), which fits the description of organizations that depend on volunteer service and influence policymaking.