While developing an application following the 12-factor app methodology, which approach should be used in the application for logging?

While developing an application following the 12-factor app methodology, which approach should be used in the application for logging?
A . Write a log to a file in the application directory.
B . Write a log to a file in /var/log.
C . Write the logs buffered to stdout.
D . Write the logs unbuffered to stdout.

Answer: D