A developer at a company writes an AWS CloudFormation template. The template refers to subnets that ere created by a separate AWS CloudFormation template that the company's network team wrote. When he developer attempts to launch the stack for the first time, the launch fails.
Which template coding mistakes could have caused this failure? (Choose two.)

A. The developer's template does not use the Ref intrinsic function to refer to the subnets.
B. The developer's template does not use the ImportValue intrinsic function to refer to the subnets.
C. The Mappings section of the developer's template does not refer to the subnets.
D. The network team's template does not export the subnets in the Outputs section.
E. The network team's template does not export the subnets in the Mappings section.