Linda Had a Swimming Pool Constructed at Her House

Linda had a swimming pool constructed at her house. Her physician advised and prescribed to her that the pool would slow the effects of her degenerative disease. The pool was not suitable for recreational use. Prior to the construction of the pool, the fair market value of her house was $172,000. After the construction of the pool, the appraised fair market value of the house was $181,000. The cost of the pool was $13,000. What is the amount of Linda's qualified medical expense (before considering limits based on AGI) ?

A) $0
B) $13,000
C) $9,000
D) $4,000