In response to Russian exploration, which two cities were established by the Spanish in the late 18th century?

The establishment of San Diego and San Francisco in the late 18th century was part of Spain's effort to solidify its presence in North America amid Russian exploration and expansion. San Diego, founded in 1769, was the first mission and presidio in California, serving as a critical point for Spanish colonial interests and a buffer against Russian advances from the north. San Francisco followed with its mission founded in 1776, further extending Spanish influence along the West Coast. These cities were central to Spain’s strategy of establishing settlements and missions, which aimed to convert Native Americans to Christianity and reinforce Spain’s territorial claims in the region.

The other options include cities that either do not correspond to the timeframe specified or do not have the same historical significance regarding Spanish responses to Russian exploration.