Today is $\frac{1}{7}\frac{?}{2021},$ John plans to deposit $$500$ at the beginning of each month into an

investment fund. The first deposit will be deposited today. John predicts that the

return rate of this fund will be $j_2=2\mathrm{.}23\%$ from $\frac{1}{7}\frac{?}{2021}$ to $\frac{30}{9}\frac{?}{2021}$

and $j_2=4\mathrm{.}3\%$ from $\frac{1}{10}\frac{?}{2021}$ to $\frac{31}{12}\frac{?}{2021}.$ What will be balance amount of this

account on $31/12/2021?$ Round your answer to three decimal places.

a$.3032\mathrm{.}601$

b$.3033\mathrm{.}695$

c$.3032\mathrm{.}335$

d$.3031\mathrm{.}814$