Fact 1: Infection can cause bodily tissues to swell.

Fact 2: Connective tissue is the common network for bodily systems and energy pathways.

Given the two facts above, answer the question "What can cause connective issues to swell?" with the following options: 
- infection
 - flooding
 - smoking
 - worms
 - water
 - bacteria
 - zygotes
 - air


 

 infection        