The correct answer is: A) The southern states accepted the compromise because, despite allowing California to become a free state, it strengthened federal fugitive slave laws, indicating that they were most concerned about the status of slavery at the federal level.
The Compromise of 1850 was a series of legislative measures aimed at resolving disputes related to slavery and territorial expansion. Southern states were primarily concerned about protecting the institution of slavery and its expansion into new territories. The strengthening of federal fugitive slave laws reassured them that their interests regarding slavery would be maintained at the federal level, even though California was admitted as a free state.