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? 1.It is the product of the initial amount and the additional amount after d days. 2.It is the sum of the initial amount and the number of days, d. 3.It is the difference between the initial amount and the additional amount after d days. 4.It is the sum of the initial amount and the additional amount after d days.