A Flight School Operates 5 Different Types of Airplanes

Multiple Choice

A flight school operates 5 different types of airplanes. All airplanes are outdated and require some modifications. The school has $33 000 available in the budget for airplane modification this year. An aviation engineer came up with this plan to update all airplanes. The plan's costs are shown in the following table: Which airplane modification does the school have to postpone till next year?

A) 1
B) 2
C) 3
D) 4
E) 5