Which of the following is a vector quantity?

The vector sum of a system of non-collinear forces acting on a rigid body is given to be nonzero. If the vector sum of all the torques due to the system of forces about a certain point is found to be zero,does this mean that it is necessarily zero about any arbitrary point?

$A$ rod of length $l$ is acted upon by a couple as shown in the figure. The moment of the couple is $\tau \text{ Nm}$. If the force at each end of the rod is $F$,then the magnitude of each force is (given $\sin 30^{\circ} = \cos 60^{\circ} = 0.5$):

Find the torque of a force $\vec{F} = 7 \hat{i} + 3 \hat{j} - 5 \hat{k}$ about the origin. The force acts on a particle whose position vector is $\vec{r} = \hat{i} - \hat{j} + \hat{k}$.

$A$ force of $40\, N$ acts on a point $B$ at the end of an $L$-shaped object,as shown in the figure. The angle $\theta$ that will produce the maximum moment of the force about point $A$ is given by:

Find the torque of a force $\overrightarrow F = 2\hat i + \hat j + 4\hat k$ acting at the point $\overrightarrow r = 7\hat i + 3\hat j + \hat k$.