This topic examines the board of directors of joint-stock companies. The board meeting shall be attended by the directors themselves. If a director is unable to attend for some reason, he may entrust other directors to attend in writing, and the power of attorney shall specify the scope of authorization. A made a mistake in "telephone entrustment" and B made a mistake in "entrusting the secretary of the board of directors". C: The board meeting can only be held when more than half of the directors are present. The resolution made by the board of directors must be passed by more than half of all directors, so the resolution is not established. D: If the resolution of the board of directors violates laws, administrative regulations, articles of association or resolutions of the shareholders' meeting, thus causing serious losses to the company, the directors participating in the resolution shall be liable for compensation to the company. However, if it is proved that an objection was expressed during the voting and recorded in the minutes of the meeting, the director may be exempted from liability.