In June of the current year, Susan's mother gave her 100 shares of a listed stock. The donor's basis for this stock, which she bought 10 years ago, was $4,000, and market value on the date of the gift was $3,000. Susan sold this stock in July of the current year for $3,500. The donor paid no gift tax. What was Susan's reportable gain or loss in the current year on the sale of the 100 shares of stock gifted to her? a. $0 b. $500 gain c. $500 loss d. $1,000 loss