Consider a simple example.
1) A and B are two persons 17km apart.|<-----------17------------>|
\(A\quad \quad \quad \quad \quad \quad \quad \quad B\)
Now, B has a broken leg and can't walk. So, A walks and stays at a distance of 4 km from B.
\(\quad \quad \quad \quad \)|<-----4----->|
\(\quad \quad \quad \; A \quad \quad \quad \quad \quad B\)
Now, how much distance did A walk? 13kms.
Just replace A with the Origin(0,0) and B with the coordinates of the point. The origin moved 13units to the right(X-axis) to make B 4kms away from it ----(1)
2) X & Y are two persons 29kms apart.|<-----------29------------>|
\(X\quad \quad \quad \quad \quad \quad \quad \quad Y\)
Now, X is spying on Y. So, X needs to get close and be at a distance of 17kms so as to watch Y with powerful binaculars. (Those are military grade, so can zoom 17x kms)
\(\quad \quad \quad \quad \)|<-----17----->|
\(\quad \quad \quad \; X \quad \quad \quad \quad \quad Y\)
Now, how much distance did X go? 12kms. Lets just say instead East to West, X & Y are aligned South to North.
Thus, X moved 12 units North.
Just replace X with the Origin(0,0) and Y with the coordinates of the point. The origin moved 12 units to the North(Y-axis) to make Y 17units from it ----(2)
Combining (1) & (2), The origin moved 13units in positive X axis & 12units in positive Y axis. Thus the origin now is at (13,12) at a safe distance spying on Y.
Answer (D) (13,12)