A developer is automating a new application deployment with AWS Serverless Application Model (AWS SAM). The new application has one AWS Lambda function and one Amazon S3 bucket. The Lambda function must access the S3 bucket to only read objects.
How should the developer configure AWS SAM to grant the necessary read privilege to the S3 bucket?

A. Reference a second Lambda authorizer function.
B. Add a custom S3 bucket policy to the Lambda function.
C. Create an Amazon Simple Queue Service (SQS) topic for only S3 object reads. Reference the topic in the template.
D. Add the S3ReadPolicy template to the Lambda function's execution role.