Owen receives $10 and puts it into his savings account. he adds $0.50 to the account each day for a number of days, d, after that. he writes the expression 10+0.5(d−1) to find the amount of money in his account after d days. which statement about his expression is true? a) it is the product of the initial amount and the additional amount after d days. b) it is the sum of the initial amount and the number of days, d. c) it is the difference between the initial amount and the additional amount after d days. d) it is the sum of the initial amount and the additional amount after d days.