California 540 tax Please show how you get the answer

Janet works for a company that requires her to complete work at home on a regular basis. She has an office set up in a small 100 square foot room, which is used exclusively to get work done for her employer. During the year, Janet paid $300 to have the room painted. She would like to claim an office-in-home deduction for the expenses related to her home office. Janet used actual expenses last year to figure her office-in-home deduction. Still, since her office is small and she doesnt wish to keep records of all the expenses, she has decided to use the simplified method to figure her deduction this year. How much is Janets allowable deduction for the business use of her home?

a) $800 b) $300 c) $500