Q$).$ In the formula vec$(F)=$qvec$(v)$vec$(B)$ :

A$)$ vec$(F)$ must be perpendicular to vec$(v)$ but not necessarily to vec$(B)$

B$)$ vec$(F)$ must be perpendicular to vec$(B)$ but not necessarily to vec$(v)$

C$)$ vec$(v)$ must be perpendicular to vec$(B)$ but not necessarily to vec$(F)$

D$)$ all three vectors must be mutually perpendicular

E$)$ vec$(F)$ must be perpendicular to both vec$(v)$ and vec$(B)$