Given below are two statements. One is labelled as Assertion (A) and the other is labelled as reason (R). 

Assertion (A):  Magnetic field lines are continuous and closed.

Reason (R): Magnetic monopole does not exist.

In the light of the given statements, choose the correct answer from the options given. 

Magnetic lines are imaginary lines. Within the magnet, they move from south pole to north pole and outside the magnet they move from north pole to south pole. Hence, magnetic lines form continuous closed loops. 

A magnetic monopole does not exit and magnets always exits with two poles with magnetic field lines stating from north pole and reaching south pole. Therefore the reason is true and does explain the assertion given.