Assertion (A) : Radio waves bend in a magnetic field. Reason (R) : Radio waves are electromagnetic in nature. Code:

Reason (R) is true: radio waves are a form of electromagnetic radiation, solutions of Maxwell’s equations that propagate as electromagnetic waves [1]. Assertion (A) is false in the sense implied: a static magnetic field exerts the Lorentz force on charged particles and thus deflects moving charges, not neutral photons; magnetic deflection of particle trajectories is a charged-particle effect described by the Lorentz force [2]. Photons carry no electric charge, so a static magnetic field does not directly bend radio-frequency electromagnetic waves in free space. (Electromagnetic waves can, however, have their propagation modified indirectly when traveling through magnetized media or plasmas.)

Sources

1. [2] https://www.jpl.nasa.gov/nmp/st5/SCIENCE/magnetosphere.html