I'm pretty sure it is D. This is because there are x pennies, 0.01 is how much a penny is, and y nickels, with 0.05 as the amount of 1 nickel. Dylan's brother told him to take out AT LEAST 6 coins from the piggy bank, and that sign at the end (between 0.05y and 6, i dont have the sign on my keyboard) means at least. So, I think its D.
