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:
[tex]\begin{gathered} \lvert{u}\rvert=\sqrt{9^2+12^2} \\ \lvert{u}\rvert=\sqrt{81+144} \\ \lvert{u}\rvert=\sqrt{225} \\ \lvert{u}\rvert=15 \end{gathered}[/tex]
Therefore, the correct answer is 15.
