Answer:

Step-by-step explanation:
n is an unknown number
"the product" means multiplication
and "the sum" is addition
We're going to use the compounded intrest formula:

Where P is the initial cost
r is the rate as a decimal
n is the amount per year that you invest the rate
t is the amount of time at which you're checking how much it's worth (yrs)
Using this information, we can use:

So your answer will be
B.