Final answer:
The challenge for human resource management during mergers is the seamless integration of organizational cultures, which can impact employee morale and lead to increased turnover if not managed well.
Step-by-step explanation:
According to the text, a challenge for human resource management during mergers is the seamless integration of organizational cultures. Mergers and acquisitions often involve a duplication of services, necessitating a merging of departments and the likely reduction of staff, which can lead to job loss for some employees. Among the challenges faced, seamless integration of organizational cultures is critical because employees must adjust to the new merged culture, which may differ significantly from the original cultures of the merging companies. This adjustment can be stressful and can lead to issues if not managed properly, such as a significant impact on employee morale and potentially increased turnover if employees do not feel connected to the new, combined organization.