The correct answer is (d) document.origin
To explain: Properties of DOM method are: document.anchors, document.applets, document.baseURI, document.body, document.cookie, document.doctype, document.documentElement, document.documentMode, document.documentURI, document.domain, document.domConfig, document.embeds, document.forms, document.head, document.images, document.implementation, document.inputEncoding, document.lastModified, document.links, document.readyState, document.referrer, document.scripts, document.strictErrorChecking, document.title and document.URL.