The correct answer is A. IEEE 802.11.
IEEE 802.11 is a set of standards for wireless local area networks (WLANs). It defines the physical layer (PHY) and medium access control (MAC) layer protocols for WLANs. The PHY layer specifies the modulation and coding schemes used to transmit data over the air, while the MAC layer specifies how devices access the shared wireless medium.
IEEE 802.11 has been adopted by many vendors and is widely used in a variety of applications, including home networking, office networking, and hot spots.
The other options are incorrect for the following reasons:
- IEEE 802.16 is a set of standards for fixed wireless access (FWA). It defines the PHY and MAC layer protocols for FWA systems, which are used to provide high-speed data services to fixed locations.
- IEEE 802.15 is a set of standards for personal area networks (PANs). It defines the PHY and MAC layer protocols for PANs, which are used to connect devices within a short range, such as within a home or office.
- IEEE 802.3 is a set of standards for wired local area networks (LANs). It defines the PHY and MAC layer protocols for LANs, which are used to connect devices within a building or campus.