About $802\mathrm{.}3$ Ethernet, hubs and switches

$($i$)$ Early $10$Mbps $802\mathrm{.}3$ Ethernet is $1-$Persistant CSMA$/$CD $($CSMA:Carrier Sense Multiple Access, CD: Collision

Detection$).$ Briefly explain how $1-$Persistant CSMA$/$CD functions.