What Factor Led to the Abolition of Slavery in the North

What factor led to the abolition of slavery in the North?

A) The North's economy was not as dependent on slavery as was the South's.
B) The South was more likely to believe that God accepted slavery - religion was not as important in the North.
C) The North had never had slavery, except in some areas of New York, so it wasn't widespread.
D) Everyone in the North accepted the ideas of freedom for all from the beginning of their colonies