In order to set up her dental practice, Jacqui borrowed $500,000 from her bank at a stated annual interest rate of 6%, compounded monthly. She agreed to repay the loan in equal monthly payments of $3,582.16 over 20 years. Immediately after making her 10th monthly payment, Jacqui enjoyed a sizable lottery win and decided to repay the loan. What was the outstanding balance on the loan immediately after the 10th payment?

a) $464,178.40 b) $488,748.45 c) $488,931.64 d) $489,178.40