A result of the official system of slavery in the American colonies is A. Plantations began to lose money due to the costs of slavery.
The official system of slavery in the American colonies regarded slaves as property to be bought and sold, and forced to work.
However, the Emancipation Proclamation of 1863 by President Abraham Lincoln, in the thick of the Civil War, marked the beginning of freedom for enslaved African Americans.
Thus, a result of the official system of slavery in the American colonies is A. Plantations began to lose money due to the costs of slavery.
Learn more about slavery in the American colonies at https://brainly.com/question/6530278
#SPJ1