Final answer:
The article by Vakola and Nikilaou explores the impact of leadership on change at an organizational level.
Step-by-step explanation:
The subject explored in the article by Vakola and Nikilaou is leadership and how it impacts change at an organizational level. The article focuses on how leadership behavior and characteristics of individuals can influence organizational change processes. For example, leaders who demonstrate tolerance and adaptability are more likely to foster a culture of change in their organizations.