Chris is incarcerated and working under an agreement between the Department of Corrections and the California Department of Forestry to perform weed abatement in several dry brush areas near the prison. Chris earned $700 for work under the agreement and $300 for working in the kitchen during the current tax year. Chris regular tax liability is 3% of earned income. What is the amount of Chris tax liability after applying the credit, assuming there is a credit?

a.$0

b.$30

c.$40

d.$70