The correct answer is D, boards.
JIRA is a tool for agile project management, while Azure DevOps is a set of development tools, services, and features that enable teams to plan, develop, deliver, and maintain software more efficiently. While Azure DevOps does include a build pipelines service, it is not a replacement for JIRA. Instead, Azure DevOps has a feature called Azure Boards, which is a tool for agile project management similar to JIRA.
Azure Repos is a version control system that is part of Azure DevOps, and Azure Release Pipelines is a service for creating and managing automated release pipelines for your applications. However, neither of these is a replacement for JIRA.
Therefore, the statement "When moving to Azure DevOps, JIRA must be replaced with the build pipelines Azure DevOps service" is not accurate, and the correct answer is D, boards.