Answer: 1. Ensure you have the project billing administrator role. 2. Select the associated billing account. 3. Create a budget and alert for the specific project.

Option A is correct because it specifies the need for the project billing administrator role to access and manage billing information, followed by creating a budget and alert for the specific project. This approach directly addresses the requirement to monitor individual projects within the same billing account. Options B, C, and D are incorrect due to either unnecessary steps (like creating a custom alert in B) or incorrect role specifications (project administrator instead of billing administrator in C and D). For more details, refer to [Google Cloud Billing documentation](https://cloud.google.com/billing/docs/how-to/budgets).

Author: LeetQuiz Editorial Team