_____ describes interactions between organizational units on the same hierarchical level.

A) Peripheral communication
B) Vertical communication
C) Horizontal communication
D) External communication

Horizontal communication pertains to interactions between organizational units on the same hierarchical level. Peripheral communication refers to communication between an organization and its external environment, while vertical communication pertains to interactions between different hierarchical levels within an organization. External communication refers to communication between an organization and its stakeholders outside of the organization.