A force of $-F\hat{k}$ acts on $O$, the origin of the coordinate system. The torque about the point $(1, -1)$ is (1) $-F(\hat{i} - \hat{j})$ (2) $F(\hat{i} - \hat{j})$ (3) $-F(\hat{i} + \hat{j})$ (4) $F(\hat{i} + \hat{j})$
A force of $-F\hat{k}$ acts on $O$, the origin of the coordinate system. The torque about the point $(1, -1)$ is\\
(1) $-F(\hat{i} - \hat{j})$\\
(2) $F(\hat{i} - \hat{j})$\\
(3) $-F(\hat{i} + \hat{j})$\\
(4) $F(\hat{i} + \hat{j})$