One of Your Primary Business Objectives Is Being Able to Trust

One of your primary business objectives is being able to trust the data stored in your application. You want to log all changes to the application data. How can you design your logging system to verify authenticity of your logs?

A) Write the log concurrently in the cloud and on premises
B) Use a SQL database and limit who can modify the log table
C) Digitally sign each timestamp and log entry and store the signature
D) Create a JSON dump of each log entry and store it in Google Cloud Storage