During which part of the plot does conflict develop?

try Exposition. :)

Explanation:

1) Exposition (introduction) - Beginning of the story; characters, background, and setting revealed. 2) Rising Action - Events in the story become complicated; the conflict is revealed. These are events between the introduction and climax.

the red coloration of the lungs looks alarming and adds to the overall message that the flu is threatening apex

i believe that's the correct answer