C

Explanation:
In the appraisal process, after action plans are agreed upon, the next stage is follow-up. This involves monitoring the implementation of the agreed action plans, ensuring that the employee is making progress toward the set goals, and providing any necessary support or adjustments. Option A (training programme) may be part of the action plan but is not a distinct stage. Option B (set objectives for the future) typically occurs during or before the agreement on action plans. Option D (the appraisal interview) precedes the agreement on action plans, as it is where discussions and agreements are made.