Your team is working on an API definition that will be deployed using the API gateway service. You then need to ensure that control is established on who can access the various resources within the API gateway. Which of the following can help ensure this security requirement is met? Choose 3 Options.

Answer options:

A.Key Policies
B.IAM Policies
C.Resource Policies
D.IAM Roles

Answer - B, C and D
This is given in the AWS Documentation.
For more information on using IAM Policies for controlling access, please refer to the below URL-
https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-control-access-using-iam-policies-to-invoke-api.html
Resource policies, Iam roles and policies can control access to an API.
https://docs.aws.amazon.com/apigateway/latest/developerguide/apigateway-control-access-to-api.html