a. Removing Impediments
b. Facilitating meeting as and when requested
d. Consulting the Development Team and Product Owner
Reasoning
Scrum Master is the person who is responsible for facilitating/coaching the Development Team and the Product Owner to work on the day to day development activities. He is the one who ensures that the team understands the Scrum Values and Principles and is able to practice them.
At the same time, Scrum Master also assures that the Team feels enthusiastic about Agile in order to achieve the best out of the framework. Scrum Master also helps and supports the team to become self-organized and removes impediment for them.