b. The attorney?
The attorney apparently would be the right person to keep custody of the EPA. After all, the attorney should be a person who is close to the donor and trusted by the donor. The attorney will also be the person responsible for exercising the authority as specified in the EPA. It seems that the attorney appears to be the appropriate person for keeping custody of the EPA.
Despite the above ideal scenario, we have to face the sad reality that people can change; after the execution of the EPA, the attorney may change to an extent that the donor loses all trust and confidence in the attorney. In such circumstances, if the donor wants to get back the EPA, the attorney may refuse to do so. The donor will then have to resort to revoking the EPA and perhaps having to make a new one by appointing another attorney. Therefore, a donor should act promptly to revoke an EPA if it is in the custody of an attorney whom the donor no longer trusts.