Which Parties May Choose to Use Conventions Rather Than Primary

Which parties may choose to use conventions rather than primary elections to nominate candidates?

A) any party that had a nominee on the ballot in the last gubernatorial election
B) parties that won between 2 percent and 20 percent in the last gubernatorial election
C) the party that won the last presidential election
D) the party that won the last gubernatorial election
E) only Democrats and Republicans