In current SFRA, the endpoint that renders a content asset as a full storefront page isPage-Show, and it expects the content asset ID in thecidquery-string parameter. Salesforce ' s SFRA Page controller documentation explicitly definesPage-Showas rendering a content asset in a full storefront page and documentscidas the ID of the content asset.
Therefore, the correct generated URL is equivalent to:
Page-Show?cid=about-us
and the correct ISML link is option B as corrected above.
Content-Showis not the current SFRA full-page content endpoint used by the base Page controller, whileContent-Pageis not the corresponding route. Salesforce ' s Page Designer/link-builder documentation also demonstrates URL components in the form[ " Page-Show " , " cid " , " < id > " ].
Study Guide reference:Application Development -Page-Show,URLUtils.url(), content assets,cid, storefront links, and SFRA routing.