Giben the triangles:
ABC and PQR
Thiangle PQR is a reduction of triangle ABC, this means that the sides of triangle ABC were divided by a reduction factor to determine the side lengths of triangle PQR.
Using the lengths of sides AB and its correspoding side PQ you can calculate the used reduction factor k following the formula:

Using this relationship you can determine the value of the reduction factor

The reduction factor is k=4
Now that we have determined the factor, we can calculate the length of PR as:

The length of PR=6, so the correct option is C.