Answer:
C. To end the practice of slavery
Step-by-step explanation:
The Knights of Labor was an American labor force in the 19th century that sought to improve the living condition of its members that were low skilled, or unskilled workers.
Their major aims and objectives were to limit working hours to eight hours daily, end child labor, get equal pay, and better living and working conditions generally.
Ending the practise of slavery was not one of the objectives of the Knights of Labor