A courier company is looking at insuring themselves against claims where items get lost during delivery. They estimate that in the previous year, 20 items were lost, and that each case cost approximately 120 in compensation. They are currently looking at an insurance policy which will cost 150/month and will cover the costs of the first 2 claims each month.

(a) What is the best probability distribution to model the number of lost items in a month? Give reasons for your answer.