The intention behind this question is to INDIRECTLY ask the responsibilities of the Scrum Master or a LEADER. He is expecting the real-time experience which you have faced.

Every team will GO through 4 stages of group development which is Forming, Storming, Norming, and Performing.

• Forming-
   Most team members are new, polite and humble at this STAGE also the roles and responsibilities are not clear to the team.
• Storming- 
  Storming can also happen in other situations. Example: Team members may challenge your authority, or jockey for position as their roles are clarified. Or, if you haven't defined clearly how the team will work, people may feel overwhelmed by their workload, or they could be uncomfortable with the approach you're using. This is the situation where many teams fail.
• Norming-
   This is when people start to resolve their differences, appreciate colleagues' strengths, and respect your authority as a leader.
• Performing- 
  The team reaches the performing stage, when hard work leads, without friction, to the achievement of the team's goal. The structures and processes that you have set up support this well.

As a leader, you can delegate much of your work, and you can concentrate on developing team members.

The same is depicted in the figure below.

As a leader, we should handle this situation very diligently. My approach could be:

1. Analyze the reason for conflict.
2. Talk to the team members individually and try to understand them from their perspective.
3. You should make them understand the COMMON goals of the team and work towards it, as Scrum always believe in collaboration over tools and processes.
4. Guide them to take criticism as a step towards your success goals.
5. Do more frequent team outings and team building events.
6. After each sprint completion appreciates the efforts put in by each team member and celebrate this by organizing small snacks or lunch get together after retrospection.