Bill and Betty Ma owned half of a two- unit residential building. Betty lived in the unit, but Bill did not. To collect a judgment against the Mas, Mei- Fang Zhang obtained a writ of execution directing the sheriff to seize and sell the building. State law allowed a $ 100,000 homestead exemption if the debtor lived in the home and $ 175,000 if the debtor was also disabled and “unable to engage in gainful employment.” Bill argued that he could not work because of “gout and dizziness.” How much of an exemption are the Mas entitled to have? Why?