Which set of ordered pairs represents y as a function of x? A. {(2, 5), (3, 1), (4, 1), (4, 7)}

B. {(3, 2), (4, 3), (3, 2), (2, 6)}

C. {(1, 3), (3, 5), (2, 5), (1, 6)}

D. {(6, 7), (4, 6), (-4, 4), (5, 1)}

Harry owes the bank money. to repay his debt, he paid $150 back to the bank each month. after 10 months, his remaining debt was $6900. what was the original amount of harry's debt? how long did it take harry to pay back his entire debt?