Answer:
3 and 8 are the extremes of the given proportion (first listed answer option)
Explanation:
In a proportion of the type:
the values "A" and "D" are called "extremes of the proportion, while "B" and "C" are called the "means" of the proportion.
This comes from writing it as: A : B = C : D
where we observe that A and D are the more "extreme" values being further away from the equal sign than the quantities B and C which are more towards the middle (center of the proportion).
So in your case, the numbers 3 and 8 are the extremes