1.(08.01 MC) What did Missouri, Kentucky, Maryland, and Delaware have in common during the Civil War? (5 points)
They were all slave states that had remained in the Union.
They were the first Confederate states to be captured by the Union army.
They all declared their neutrality during the war.
They freed their slaves before the Emancipation Proclamation was issued.

i think the answer is c, rivers.

explanation:

sometimes, borders fall along natural boundaries like rivers or mountain ranges. for example, the boundary between france and spain follows the crest of the pyrenees mountains. for part of its length, the boundary between the united states and mexico follows a river called the rio grande. the borders of four countries divide africa’s lake chad: niger, chad, cameroon, and nigeria.

c) troops march forward in close formation against newer, more accurate weapons