You support an application deployed on Compute Engine. The application connects to a Cloud SQL instance to store and retrieve data. After an update to the application, users report errors showing database timeout messages. The number of concurrent active users remained stable. You need to find the most probable cause of the database timeout. What should you do?

A. Check the serial port logs of the Compute Engine instance. B. Use Stackdriver Profiler to visualize the resources utilization throughout the application. C. Determine whether there is an increased number of connections to the Cloud SQL instance. D. Use Cloud Security Scanner to see whether your Cloud SQL is under a Distributed Denial of Service (DDoS) attack.