Clementine is part owner of a mining venture. A saver by nature, she puts part of her profits into a 6% savings account every other month. The first month she deposited $50. She has increased each of three subsequent deposits by $10. If she wants to fore- cast what the account balance will be after 10 months, she should use which of the following tables?
a. Future value of a single sum
b. Future value of an annuity
c. Present value of a single sum
d. Present value of an annuity