Answer: Choice C
Step-by-step explanation:
Segment LM is 7 units long compared to L'M' which is 21 units long. You can count out the spaces between the points, or use subtraction and absolute value, to find these segment lengths.
The jump from 7 to 21 is "times 3" which is directly from the scale factor 3. Each length of the image is 3 times larger compared to the preimage counterpart. Therefore, K'L' will be 3 times longer compared to KL.