What is the torque of the force $\overrightarrow {F}=-3 \hat i +\hat j+ 5 \hat k$ acting at a point whose position vector vector is $\overrightarrow {r}= 7 \hat i+3 \hat j +\hat k?$

Question

$$\begin {array} {1 1} (a)\; 14 \hat i- 38 \hat j + 16 \hat k & \quad (b)\;4 \hat i+ 4 \hat j + 6 \hat k \\ (c)\;-14 \hat i+ 38 \hat j - 16 \hat k & \quad  (d)\;-21 \hat i+ 3 \hat j + 5 \hat k \end {array}$$