Final answer:
The key legal issue to establish in a cloud computing contract is the procedure for retrieving and deleting information from the provider's systems if the contract is canceled, especially to safeguard the privacy of electronic health records.
Step-by-step explanation:
A key legal issue that should be established with a procedure ahead of signing a cloud computing contract is retrieving and deleting information from the provider's systems in the event of a canceled contract (Option A). This is vital as it addresses concerns related to the privacy of electronic information and security of data. Ensuring that you can retrieve all your data and have it deleted from the cloud provider’s systems is critical for maintaining data privacy and protecting sensitive information. This becomes even more important when the data includes digital records among health providers, as the privacy and security of health information are regulated by laws such as HIPAA in the United States.