Read the following context and choose the best option to answer the question.
Context: There is a room full of vending machines . I had a 20 dollar bill and I wanted a Coke Zero . In a quiet hour , I walked down to the emergency department and asked the clerk if there was a cashier anywhere who took payments at night , so I could get change . He sent me to the security desk , staffed by a VA police officer who told me that there was no cashier anywhere , and no change machine he could think of .
Question: Why did the narrator need to get change ?
Options: 
- They wanted to make a donation .
 - They wanted to buy themselves a snack .
 - They wanted to buy a sandwich .
 - None of the above choices .


They wanted to buy themselves a snack .