Which event in the Mexican period triggered the long-standing rivalry between northern and southern ...

Which event in the Mexican period triggered the long-standing rivalry between northern and southern California?
 
  a. Jos Mara Echeanda, the governor appointed by Mexico's federal government in 1825, decided to station himself in San Diego instead of Monterey, the existing capital.
  b. Jos Mara Echeanda, the governor appointed by Mexico's federal government in 1825, decided to station himself in Monterey instead of San Diego, the existing capital.
  c. The Chumash attacks on three missions in 1824 signaled to northern Californians that their neighbors in the South were unable to control the native population.
  d. Luis Argello, the first governor of California in the Mexican period, allowed a new mission to be established in Sonoma, despite the Mexican law disbanding the missions.