Which option does not belong to the Huawei EI Essential Platform?

The option that does not belong to the Huawei EI Essential Platform is Huawei HiAI. The Huawei EI Essential Platform comprises a suite of tools and services specifically geared towards enabling and streamlining the development and deployment of artificial intelligence applications.

Huawei HiLens is an AI development platform that provides guidance for building AI applications, particularly in smart vision. ModelArts is an integrated development environment for AI that supports the entire machine learning workflow, including data preparation, model training, and deployment. Similarly, the Graph Engine Service (ECS) offers functionalities that support the processing and analysis of graph-based data, which can be pivotal in certain AI applications.

In contrast, Huawei HiAI is a framework primarily focused on optimizing artificial intelligence capabilities on mobile devices, making it less associated with the overarching EI Essential Platform. This distinction highlights its specific use case in mobile computing rather than the broader AI services and infrastructure that the other options provide within the Huawei ecosystem.