Final answer:
Dean's charitable contribution deduction for the painting in this situation would be limited to his adjusted cost basis of $5,240.
Step-by-step explanation:
Dean's charitable contribution deduction for the painting would be based on the fair market value (FMV) of the painting at the time of the donation. In this situation, the FMV of the painting is $91,600. However, since the museum announced the sale of the painting due to its limited historical value, the deduction would be limited to Dean's adjusted cost basis of $5,240.