Option A is true
You are responsible for the licensing of all of your software. Bare Metal Solution uses a bring-your-own-license (BYOL) model.
Apart from this you are responsible for the software, applications, and data that you use and store in the Bare Metal Solution environment.
Responsibilities
Data, including:
- Security and encryption
- Backups
Software and applications, including:
- Installation
- Configuration
- Upgrades and patching
Operating system and any hypervisor, including:
- Configuration changes
- Upgrades and patching
Server clusters, including:
- Installation
- Configuration
- Maintenance
Licensing
Option B & C is also true.
With Bare Metal Solution, Google Cloud provides and manages the core infrastructure, the net-work, the physical and network security, and hardware monitoring capabilities in an environment from which you can access all of the Google Cloud services. The core infrastructure includes secure, controlled-environment facilities, and power.
The Bare Metal Solution also includes the provisioning and maintenance of the custom, sole-tenancy hardware with local SAN, and smart hands support.
The network, which is managed by Google Cloud includes a low-latency Cloud Interconnect con-nection into the customer Bare Metal Solution environment.
The available Google Cloud services include private API access, management tools, support, and billing.

The key to remember here is that for a service provided (GCP in this case) to take responsibility for its PaaS, it must offer the service as a managed service. GCP offers its own Kubernetes platform called GKE. But OpenShift is not a Google-offered PaaS solution. As such, Google will not take responsibility for the back-end operations and design of your OpenShift environments. You will need to manage all the VMs that OpenShift will provision as part of its GCP deployment. So this is an IaaS deployment from a shared responsibility model perspective.

Firebase/Firestore is easy to build and is suitable for user information that could bvary in nature.

Explanation
Because product ratings are structured because they are numerical scores.