At what layer of the osi model do the 802.11 standards vary?

The 802.11 standards are defined from IEEE and represent a set of specifications for the Media Access Control (MAC) and physical layer for the Wireless Local Area Network (WLAN) networks. The WLAN communication networks operate in the 900 MHz and 2.4, 3.6, 5, and 60 GHz frequency bands.
The 802.11 standards vary at the physical layer of the OSI model, because there it is defined at which frequency band the network operates.
 

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