Hey there!
Your question states: A highly <span>susceptible population is
. . .
The word </span>

indicates when something is most likely to happen. It also means when things have a chance of happening or it's liable to be influenced.
<span>
In this question above, we need to find something that would happen based on what you have.
</span>A highly susceptible population is<span>
people who are more likely to become sick from food-borne illness.
People who have to food-borne illness, will most likely get sick.
Your correct answer would be </span>

<span>
✓</span>
Hope this helps.
~Jurgen