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 $j_2=4\mathrm{.}81\%$ from

$\frac{1}{7}\frac{?}{2021}$ to $\frac{30}{9}\frac{?}{2021}$ and $j_2=3\mathrm{.}91\%$ 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$.3036\mathrm{.}682$

b$.3035\mathrm{.}842$

c$.3037\mathrm{.}723$

d$.3036\mathrm{.}363$