The State of Aurora requires licenses of persons "who are engaged in the trade of barbering." It will grant such licenses only to those who are graduates of barber schools located in Aurora, who have resided in the state for two years, and who are citizens of the United States. Assume that a resident of the state of Aurora was denied a license because she graduated from an out-of-state barber school. Her suit in federal court to enjoin denial of the license on this ground would be
dismissed, because there is no diversity of citizenship.  dismissed, because of the abstention doctrine.  decided on the merits, because federal jurisdiction extends to controversies between two states.  decided on the merits, because a federal question is involved