Two alternatives for a construction project are being considered. Both projects have a 7-year life. Alternative A has an initial cost of $2,000 and yields $585 annually for 7 years. Alternative B initially costs $4,500 and yields $1,100 annually for 7 years. The rate of return on the difference between the alternatives is approximately:

• 10.1%
• 22.0%
• 15.6%
• 6.4%