Question

when california applied for statehood, southern states feared
they would lose equality in the senate.
enslaved workers would escape.
they would have to pass new laws to maintain slavery.
the gold - mining industry would overtake agriculture.

Explanation:

The question is about the concerns of Southern states when California applied for statehood. The key context is the balance of power in the Senate regarding slavery (free vs. slave states). Southern states feared losing equality in the Senate (i.e., equal representation of slave and free states) if California (a free - state - likely) was admitted, as it would upset the balance. The other options: "enslaved workers would escape" is not the main fear here; "they would have to pass new laws to maintain slavery" is not the primary concern related to California's statehood; "the gold - mining industry would overtake agriculture" is an economic concern not related to the political balance of power which was the main issue.

Answer:

A. they would lose equality in the Senate.