The correct answers are C) county and D) state.
The types of conventions that came into being after 1830 were county and state.
In a county convention, delegates will assemble to elect county officers and delegates for the state convention. Delegates serve a two-year term. Then after the county convention, the delegates go to the state convention. Let's remember that political conventions are the events where the candidates for the president of the United States are nominated. During the convention, the party can discuss the actual party's platform. Today, a political convention is a huge event where modern light and sound systems, as well as scenography, and media coverage play a big role in the emotion of the people.