Calculating taxes on security transactions. If Brenda Doran is single and in the 28 percent tax bracket, calculate the tax associated with each of the following security transactions. (Use the IRS regulations for capital gains in effect in 2014.) Treat each of the following cases as independent of the others. A. She sold stock for $1,200 that she purchased for $1,000 5 months earlier. B. She sold bonds for $4,000 that she purchased for $3,000 3 years earlier. C. She sold stock for $1,000 that she purchased for $1,500 15 months earlier.