Final answer:
To calculate the perpetual annual worth of an alternative with a 5-year life, you need to multiply the annual worth by the interest rate, which is denoted as i.
Step-by-step explanation:
To calculate the perpetual annual worth of an alternative with a 5-year life, you need to multiply the annual worth by the interest rate, which is denoted as i. Therefore, the correct option is Option a: Multiplying the annual worth by i. This calculation takes into account the present value of future cash flows and the interest rate to determine the equivalent annual worth.