Answer I think A
Step-by-step explanation:
we know that
The formula of simple interest is equal to

In this problem
we have
I=$170
P=$8,500
r=4%=4/100=0.04
t=?
substitute given values in the formula

therefore
0.5 years=6 months
<h2>The answer is 6 months</h2>
More people have grown up or more people have found jobs
Hope this helps....
--------------------------------------------------------------------------------