Hansel and Gretel, a married couple, manage apartments and they are required to live in the managers apartment asa condition of their employment. Instead of providing the apartment to Hansel and Gretel rent-free, the owner of theapartment building gives Hansel and Gretel a housing allowance of $600, which they use to pay rent on the managersapartment. Hansel and Gretel pay $600 per month in rent. If they did not live in the managers apartment, Hansel andGretel could live in another apartment building where they would only pay $500 in rent. What amount, if any, must beincluded in Hansel and Gretels gross income?

1. $0.

2. $100.

3. $500.

4. $600.