A)
[tex]\bf \qquad \textit{Amount for Exponential Growth}\\\\
A=P(1 + r)^t\qquad
\begin{cases}
A=\textit{accumulated amount}\\
P=\textit{initial amount}\to &200000\\
r=rate\to 0.6\%\to \frac{0.6}{100}\to &0.006\\
t=\textit{elapsed time}\to &t\\
\end{cases}
\\\\\\
A=200000(1+0.006)^t\implies A=200000(1.006)^t[/tex]
B) [tex]\bf A=200000(1.006)^4[/tex]