Mary volunteers 10 hours per week at a local food bank (a qualified charity) helping to prepare meals for the homeless. Marys day job, for which she is paid $20/hour, is as a chef at a local restaurant. How much is Mary allowed to claim as a charitable service contribution?

a. Half of what she would have earned had she gone to her paid job

b. All of what she would have earned had she gone to her paid job

c. No deduction at all, she is just a good person

d. It depends