In the context of political conventions, what is the primary role of delegates, and how are they typically selected?
a) Delegates serve as campaign advisors for candidates and are selected by party officials.
b) Delegates represent the voters of their state or district in selecting the party's nominee and are chosen through primary elections, caucuses, or party conventions.
c) Delegates are responsible for drafting party policy and are appointed by the party's national committee.
d) Delegates act as fundraisers for the party and are elected by the general public during the national election.