Line segment XY is dilated to create line segment X Y using point T as the center

Line segment XY is dilated to create line segment X'Y' using point T as the center of dilation. Point T is the center of dilation. Line segment X Y is dilated to create shorter line segment X prime Y prime. The length of T X prime is 6 and the length of T Y prime is 9. The length of X X prime is 2.

What is YT?

3 units
6 units
12 units
15 units