When using DiffServ $($Differentiated Services$),$ what type of forwarding utilizes a minimum departure rate from a given node?

a$.$

AS $($Assured Forwarding$)$

b$.$

PF $($Prioritized Forwarding$)$

c$.$

SF $($Scaled Forwarding$)$

d$.$

EF $($Expedited Forwarding$)$