Luis and Sara both open savings accounts at the same bank. Luis opens his account with $125 and deposits $60 per week. Sara opens her account with $50 and increases the amount by 4% per week. Which account has a greater average rate of change between 10 and 20 weeks?

A. Luis's account has a smaller average rate of change than Sara's account between 10 and 20 weeks.
B. Sara's account has a greater average rate of change than Luis' account between 10 and 20 weeks.
C. Luis's account has a greater average rate of change than Sara's account between 10 and 20 weeks.
D. Sara's and Luis's accounts have the same average rate of change between 10 and 20 weeks.