Please help me solve this

Assume you won Loto-Quebec! Instead of receiving the prize as a lump sum payment, you choose to receive $20,000 per year for 50 years. As a result of that you decide to work part-time at 30 hours per week instead of 50 hours per week. Assuming a 50- week year, what is the annual income effect equal to? O A. -1/10 O B. 1/20 O C. -1/20 O D. -1/100