According to security best practices, how should an Amazon EC2 instance be given access to an Amazon S3 bucket?
A . Hard code an IAM user’s secret key and access key directly in the application, and upload the file.
B . Store the IAM user’s secret key and access key in a text file on the EC2 instance, read the keys, then upload the tile.
C . Have the EC2 instance assume a role to obtain the privileges to upload the file.
D . Modify the S3 bucket policy so that any service can upload to it at any time
Answer: D