Missouri and maine were admitted together with which decisions involving slavery?

maine and missouri would be slave states.
maine and missouri would be free states.
maine would be a free state, and missouri would be a slave state.
maine would be a slave state, and missouri would be a free state.

The telegraph, the transatlantic telegraph cable, and the telephone were important to businesses after 1850 because of a. they created a system for developing new inventions. b. they filled a need that other inventions of the day could not. c. they attracted investors and created the stock market. d. they made picture-taking a popular american pastime.