Select the correct statement$($s$)$ regarding the use of decentralized control over a LAN, WLAN, or WPAN.

a$.$ Decentralized control represents a medium access mode in which each network node determines when it can place data onto a shared medium

b$.$ Decentralized control provides deterministic access to the medium

c$.$ The use of tokens or polling are used to enable decentralized control

d$.$ All of the above are correct