Sandy just received her annual bank statement. Exactly one year ago, she deposited $$10,000$ in a savings account. Today, her balance is $$10,509\mathrm{.}45.$ Sandy's savings account interest is compounded quarterly. Using simple interest as a guideline, Sandy received an annualized interest rate of$\_\_\_$percent. a$.5,$ b$.5\mathrm{.}5,$ c$.6,$ d$.6\mathrm{.}5$