What is the main improvement of WPA$3$ over WPA$2?$

a$.$ The Pre$-$Shared Key $($PSK$)$ has a minimum length and set of characters to meet security requirements

b$.$ The Pre$-$Shared Key $($PSK$)$ has been substituted by the Simultaneous Authentication of Equals $($SAE$)$ protocol

c$.$ It uses both the $2\mathrm{.}4GHz$ and $5GHz$ wireless frequencies for faster speeds

d$.$ The Temporal Key Integrity Protocol $($TKIP$)$ key length is $4096$ bits or higher