为自己加油

Why does the writer tell the story of his making a lemonade drink at the end of the passage?（ ）

A.
To give the reader an example of what modern life is like. 
B.
To teach the reader how to make a home-made lemonade. 
C.
To show his desire for occasional relaxation in fast-paced life.
D.
To protest against mass production of goods in industrial age.