You are managing a development project in Google Cloud. You want to ensure that you are notified immediately if the monthly spending exceeds $500. You do not want the resources to be shut down automatically.

What is the simplest way to achieve this?

Create a budget in the Cloud Billing console and set a threshold alert at 100% of the $500 amount.

Set up a Cloud Function triggered by Cloud Monitoring to check billing metrics and send an email.

Configure a budget with a Pub/Sub notification that triggers a script to disable billing on the project.

Set a quota limit of $500 on the project in the IAM & Admin console.