A CloudFormation template refers to subnets that another CloudFormation template (owned by the networking team) created. The developer's stack fails on first launch. Which template mistakes could cause this failure? (Choose two.)

For one CloudFormation stack to reference resources created by another stack, the creating stack (here, the networking team's template) must explicitly export those resource values using the Outputs section and the Export field. The consuming stack (the developer's template) then uses the Fn::ImportValue intrinsic function to retrieve these exported values. Therefore, if the networking team's template doesn't export the subnet values, the developer's template cannot import them, leading to a failure. Similarly, if the developer's template attempts to reference the subnets without using Fn::ImportValue, it will fail because it won't know how to access external stack outputs. Using Ref directly in the developer's template would only work for resources defined within that same template. The Mappings section is for defining conditional parameter values, not for cross-stack references.