How did the emancipation proclamation open a door for black soldiers

powers  are  denied  to the  national governmentin three distinct ways: some  powers, such as the  power  to levy duties on exports or prohibit the freedom of religion, speech, press, or assembly, are expressly  denied  to the  national government  in the  constitution.

your answer would be (b)

a drastic rise in oil prices ended decades of postwar.

hello,

the steamboat is your answer.

it seems like its the only form of transportation on the choices.