The action that best supports Megan's claim "Respecting leadership is an important part of the Jungle Law" is:
Shere Khan speaks as a leader because Akela is a Dead Wolf and too old to lead.
This action demonstrates how the hierarchy and respect for leadership within the Pack are pivotal themes in the excerpt. Shere Khan's attempt to take on a leadership role stems from the fact that Akela, the current leader, has lost his status (as indicated by being the "Dead Wolf"), which is an integral aspect of the Jungle Law regarding leadership and the consequences of failure.