Kathy is 60 years of age and self-employed. During 2018, she reported $524,000 of revenues and $104,800 of expenses relating to her self-employment activities. If Kathy has no other retirement accounts in her name, what is the maximum amount she can contribute to an individual 401(k) for 2018?(Round your final answer to the nearest whole number)

$55,000

$61,000

$81,125

$99,625