Indian Institute of Foreign Trade 2010 Solved Paper

The given passage talks about the diagram called stack and how it is organised.
Statement II introduces Stack.
Statement IV gives a basic overview of stack
E Statement III goes on to expand on statement IV. Hence Statements II, IV, III form a mandatory pair
Statement I says that on paper Stack seems easy, however, in real life the implementation of Stack is difficult. The premise that Stack seems easy could be reached only after explaining the basics of stack. So Statement I is the last statement.
The correct order is II,IV,III,I.