The diagram illustrates the magnetic field pattern produced by the current $I$ in a straight wire. Which row is correct?
- Adirection of field: X; relative strength of field: greater at P than Q
- Bdirection of field: Y; relative strength of field: greater at P than Q
- Cdirection of field: X; relative strength of field: greater at Q than P
- Ddirection of field: Y; relative strength of field: greater at Q than P