Answer
(a) Andre also sees a magnetic field and this magnetic field points up.
(b) Andre also sees an electric field and this electric field points into the page.
Work Step by Step
(a) As Andre is moving perpendicular to the direction of the magnetic field, Andre also sees a magnetic field and this magnetic field points up.
To see this magnetic field, Andre could observe the effect on a moving charge as there would be a force on the charge due to the magnetic field.
(b) As Andre is moving perpendicular to the direction of the magnetic field, Andre also sees an electric field and this electric field points into the page.
To see this electric field, Andre could observe the effect on a stationary charge in his frame of reference. Because the charge is moving in a direction perpendicular to the magnetic field, there would be a force on the charge due to the magnetic field. By the right hand rule, this force is directed into the page.
