Final answer:
The length of a board member's term can be extended until the next election if no new member is appointed.
Step-by-step explanation:
The question is asking about the length of a board member's term on a board if no new member is appointed. The length of a board member's term can be extended until the next election if no new member is appointed. This is not specific to any particular subject but falls under the general category of governance and organizational structure.
The answer to the question is d) Until the next election. The length of a board member's term can be extended until the next election if no new member is appointed. When no new member is appointed, a board member's term can be extended until the next election takes place and a new member is elected.