C. 250 + 6d + 4(2d)
250 is the amount of money that Andrew began with. If "d" represents the deposit, and you know that he deposited that same amount of money for the next 6 weeks, you have 6d. Since you also know that you deposited twice the amount of money for the following 4 weeks, then you know that he deposited 2d every week after that, creating 4(2d).