At what point does a union become free to strike or apply other economic pressure?

1. Virtually all labor agreements require conflicts to be settled peacefully, usually by arbitration. 2. That requirement holds for as long as the agreement itself is alive. 3. Once the contract expires and no replacement has been agreed, the peaceful settlement requirement no longer covers the dispute. 4. At that point the union is free to strike or use other economic pressure on the employer. 5. A grievance is handled under the live contract, so option A would breach the very clause the union is bound by. 6. Authorization cards belong to the organizing phase and an arbitration award ends a dispute rather than opening one, so options B and D name the wrong moments. _Source: OpenStax Introduction to Business (CC BY 4.0), Ch 8 "Managing Human Resources and Labor Relations", section Tactics for Pressuring a Contract Settlement_