have decided
has decided
are decided
is decided
本题考查主谓一致和语态。The board董事会，作为一个整体做主语时，谓语动词用单数。 因为“董事会”和“做决定”是主动关系，故排除CD选项的两个表示被动语态的选项。故选B。句意：董事会已决定不采纳这项计划。
