Answer:
A) The mower is only expected to be needed for three years.
Step-by-step explanation:
Excelsior is surely more expensive than the Grassassinator, due to its longer working life. Therefore, it is essential to examine the period of use of the lawn mower. There is absolutely no need to invest in a long-running lawn mower if it is going to be needed twice less the time. In this case, it would be more financially efficient to invest in the Grassassinator.