Your team is planning to use the AWS Code Build service to test out the build of the application. The application needs to connect to a database. How should you securely store the database password so that it is available during the build process?

Answer options:

A.Store the password as an environment variable on the build server.
B.Store the password in AWS Systems Manager Parameter Store.
C.Store the password in a config file on the build server.
D.Store the password in a config file in the application.

Answer - B
The AWS Documentation mentions the following.
We strongly discourage using environment variables to store sensitive values, especially AWS access key IDs and secret access keys. Environment variables can be displayed in plain text using tools such as the AWS CodeBuild console and the AWS CLI.
For sensitive values, we recommend you store them in the Amazon EC2 Systems Manager Parameter Store and then retrieve them from your build spec. 
All other options are invalid because they are all insecure ways to access passwords in applications from AWS CodeBuild.
For more information on referencing environment variables, please refer to the below URL-
https://docs.aws.amazon.com/codebuild/latest/userguide/build-env-ref-env-vars.html