Harry $(69)$ and Lisa $(66)$ are married. They filed separate returns and lived apart for the last eleven months of the year. Harry's gross income $($including $1/2$ of his social security$)$ for $2022$ was $$27,500.$

Up to $\_\_\_$ of Harry's social security benefits may be taxable.

$0\%$

$50\%$

$85\%$

$100\%$