The inflexibility and high levels of control exerted can________ staff, and can diminish the organizations ability to react to changing external circumstances.
句意：顽固不化和高力度的职场控制会使得职员的情绪低落，而且会减少对不断变化的外部环境做出反应的组织能力。demoralize使沮丧。defeat击败。distrust不信任。dissolve使溶解。因此选C。