Could you please help me with answer:

Kathy is 48 years of age and self-employed. During 2019 she reported $508,000 of revenues and $101,600 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)?

a)56,000

b)62,000

c)78,544

Thanks,