We need to find the modulus of the given vector:
The modulus is given by the square root of the square x-coordinate plus the square y-coordinate.
The vector is given by the origin. Hence, the x-coordinate is 9 and the y-coordinate is 12.
Then:
![\begin{gathered} \lvert{u}\rvert=√(9^2+12^2) \\ \lvert{u}\rvert=√(81+144) \\ \lvert{u}\rvert=√(225) \\ \lvert{u}\rvert=15 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/v1st1rdcympiitr7nszeuyyihz0maxraml.png)
Therefore, the correct answer is 15.