A Magento industry partner shipping provider has tasked you to build their integration module called MyCompany_ShippingProvider.
A. <option_model>MagentoConfigModelConfigOptionYesno</option_model>
B. <source_model>MagentoConfigModelConfigSourceYesno</source_model>
C. <frontend_model>MagentoConfigModelConfigFrontendYesno</frontend_model>
D. <backend_model>MagentoConfigModelConfigBackendYesno</backend_model>