Please answer A and B.

6. (Lump-Sum Tax) Two persons - A and B - earn $5,000 and $50,000 per year, respectively. Suppose the annual vehicle registration tax was $100 per vehicle per year, but it is now raised to $150. (a) (3 points) Calculate the average and marginal tax rates (if you earn $1, then how much tax do you pay for every dollar earn) for each person, before and after the tax increase. (b) (2 points) Is this tax progressive or regressive? Discuss