__________ is an extended version of the XHTML markup language for supporting RDF through a collection of attributes and processing rules in the form of well-formed XML documents.

Answer: Option A

XHTML+RDFa (Extensible Hypertext Markup Language + Resource Description Framework in attributes) is an extended version of the XHTML markup language for supporting RDF through a collection of attributes and processing rules in the form of well-formed XML documents.