Your organization has recently acquired Company A, which has its own SOC and security tooling.

Comprehensive and Detailed Explanation

The correct solution is Option A. This scenario requires both data segregation (Requirement 1) and resource sharing (Requirement 2), which is the exact use case for Google SecOps SOAR "Environments."

Google SecOps SOAR (formerly Siemplify) provides a multi-tenancy feature called Environments within a single SOAR tenant. This feature is designed for organizations that need to logically separate data and operations, such as for different business units, geographical regions, or, as in this case, a newly acquired company.

Fulfills Requirement 1 (Data Segregation): Creating a new SOAR environment for Company A ensures that all their ingested alerts and generated cases are isolated within that environment. Analysts assigned only to Company A's environment will not be able to see cases or data from the parent organization's environment.

Fulfills Requirement 2 (Playbook Sharing): Playbooks are managed at the global (tenant) level and can be shared or assigned across multiple environments. This allows Company A's analysts to access and re-purpose the pre-existing playbooks developed by the parent organization, minimizing rework.

Fulfills Requirement 3 (Minimize Effort): This is the built-in, low-effort solution. In contrast, Option D (a second tenant) would be high-effort, costly, and would make sharing playbooks extremely difficult, as tenants are fully isolated. Option B (a new role) controls permissions (e.g., view, edit) but does not inherently segregate data access. Option C (a service account) is for programmatic API access, not for human analysts working in the UI.

Exact Extract from Google Security Operations Documents:

SOAR Environments: Google SecOps SOAR supports multi-tenancy through the use of Environments.6 Environments enable you to maintain data isolation between different logical entities (such as customers, departments, or business units) within the same SOAR instance.7 Each environment functions as a separate workspace, with its own set of cases, alerts, assets, and incident data. This ensures that users and teams operating in one environment cannot access or view data in another, unless they are explicitly granted permission.

Global Resources and Playbooks: While data such as cases is segregated by environment, key SOAR components like playbooks are managed at the global scope. This allows you to create, test, and manage playbooks centrally and then make them available for use across any or all of your environments. This capability enables resource re-use and standardization of response procedures, even in a multi-tenant configuration.