#### Answer

C

#### Work Step by Step

$y=a(b^{x})$
$a$ is the initial amount. In this case $a=25000$.
$b$ is the growth factor
In this problem, we have exponential decay, so decreases by $15\%$ is translated to $85\%(100-15=85)$ or $0.85$
Thus, the equation is:
$y=25000(0.85)^x$