As a project manager, what are your primary roles and responsibilities throughout the project lifecycle? Discuss the importance of each of these responsibilities and provide examples of how you would execute them in a project scenario.

Instructions:

1. Define the role of a project manager and explain why it is important in project management.
2. Discuss the key responsibilities of a project manager during the project lifecycle, including planning, execution, monitoring, and closure.
3. Explain how each responsibility contributes to the success of the project and provide examples of how you would execute each responsibility in a project scenario.
4. Discuss the challenges that project managers may face in executing their roles and responsibilities and suggest strategies for addressing them.

Note: You should cite relevant sources to support your explanation.