Under Delaware General Corporation Law Section 253, a parent corporation that owns at least what percentage of a subsidiary's outstanding stock may effect a short-form merger without a vote of the subsidiary's shareholders?

Why D — 90%

Under DGCL Section 253, a parent corporation that owns at least 90% of the outstanding shares of each class of a subsidiary's stock may effect a short-form merger by board resolution alone, without a vote of the subsidiary's shareholders or the subsidiary's board. This is a powerful tool for completing the final step of a two-step acquisition (tender offer followed by back-end merger). However, minority shareholders still retain appraisal rights to challenge the fairness of the price.