Write a sequence to represent the total amount of money Lola has saved at the end of each month. $50, $, $, $, $, $__.
a. $70, $90, $110, $130, $150, $170
b. $60, $80, $100, $120, $140, $160
c. $55, $75, $95, $115, $135, $155
d. $65, $85, $105, $125, $145, $165