This characteristic of the Global Information Grid ensures seamless transmission of information between different service branches?

The characteristic that ensures seamless transmission of information between different service branches within the Global Information Grid is the implementation of common policy and standards. By establishing common policies and standards, various military branches can align their communication protocols, data formats, and operational procedures. This uniformity facilitates interoperability, allowing for the seamless exchange of information and ensuring that different systems can effectively communicate and understand each other.

When all branches adhere to the same policies and standards, it reduces the potential for misunderstandings or miscommunications that could arise from incompatible systems. This is particularly crucial in joint operations, where coordination between different service branches is essential for mission success.

The other options, while relevant in various contexts, do not directly address the need for standardization that underpins effective communication across different branches. Joint architecture pertains to the structural design and framework of systems but does not strictly address the interoperability aspects. Unity of command refers to the consolidation of authority under one commander, which is important for effective leadership but does not directly influence information transmission. Information services cover the services that provide data and support, but without the backbone of common policies and standards, their effectiveness in facilitating seamless communication would be compromised.