Lin received a lump-sum payment of $10,000. The payment is for social security benefits that were due her in 1991 ($7000) and 1992 ($3000). For the current year, she has a marginal tax rate of 30% and 85% of all social security benefits are included in gross income. In 1991 and 1990 to 50% of all social security benefit more included in gross income. What is the least amount of the lump-sum payment that Lin can include in this year's gross income if she does not have and cannot obtain any of her past tax forms?

A) $0 B) $5,000 C) $8,500 D) $10,000