The extremes of a proportion are the first and the last terms of the proportion. To locate the extremes, we need to identify the terms given in the proportion.
In the proportion:
[tex]\[
\frac{3}{4} = \frac{6}{8}
\][/tex]
The first term (numerator of the first fraction) is 3, and the last term (denominator of the second fraction) is 8. These are the extremes of the proportion.
So, the correct answer is:
D. 3 and 8
