The most likely reason Olaudah Equiano might have believed he had a chance to buy his freedom and move to England after being purchased by Mr. King, a “charitable and humane” Quaker merchant, is:
c. Quakers tended to be heavily involved in the abolitionist movement.
Quakers, known for their strong stance against slavery and active involvement in the abolitionist movement, would have offered Equiano hope that he could secure his freedom, especially in the context of the values that guided their actions.