There are two ways to approach this:
One:
We perform the multiplication
3488 = 3200 + 16p
We subtract 3200 from both sides of the equation.
288 = 16p
we divide by 16 so we can get the value of p
18 = p
Two:
You can substitute the choices as p and whatever number gives you the same value in each side of the equation would be the correct answer.
The answer is C. 18