The correct answer is (a) WAI ARIA
For explanation: Web Accessibility Initiative – Accessible Rich Internet Applications (WAI-ARIA) is a technical specification published by the World Wide Web Consortium (W3C) that specifies how to increase the accessibility of web pages, in particular, dynamic content, and user interface components developed with Ajax, HTML, JavaScript, and related technologies. WAI ARIA offers mechanisms to ensure that this additional interactivity remains usable independent of devices and disabilities.