You are tasked with choosing a suitable database option for a new project on Google Cloud Platform $($GCP$).$ The project requires a managed database service that allows you to allocate specific instances and incurs payment based on the allocated resources. Based on this scenario, answer the following multiple$-$choice question:

Question:

In the context of the given scenario, which database option in Google Cloud Platform $($GCP$)$ requires the allocation of an instance and payment per allocation?