Fact 1: Bacteria cause food to spoil.

Fact 2: Milk was loaded with bacteria that quickly spoiled, making it undrinkable.

Given the two facts above, answer the question "What can make milk undrinkable?" with the following options: 
- evaporation
 - Enzymes
 - boiling
 - glycogen
 - liquid
 - nutrients
 - bacteria
 - vaporization


 

       bacteria  