Identify the correct statement about the magnetic field lines
A: These start from the N-pole and terminate on the S-pole
B: These lines always form closed loops
C: Both (a) and (b) are correct
D: Both (a) and (b) are wrong

Hint:Magnetic lines of force of a magnet shows the direction in which a magnetic material will be aligned when placed at the location. Magnetic lines form a continuous, closed path. They originate from the north pole and ends to the south pole. In the magnetic field line, two lines do not cross each other. They are gathered where the magnetic field is strong, and the magnetic field line is strong near the pole.

Complete step by step answer:
The magnetic field lines tend to the North Pole to the south pole. But the magnetic field lines do not just end at the tip of the magnet. They go right into it so that inside the magnet the magnetic field positions from the south pole to the north pole. Magnetic field lines make closed rings for single magnetic poles that don't exist, unlike an electric charge.
Therefore, these lines always form closed loops and option(B) is correct.

Note: Magnetic field lines are imaginary lines that describe magnetic fields. It provides the path of magnetic force. A benefit of using magnetic field lines as a symbol is that laws of magnetism and electromagnetism can be begun using ideas like 'number' of field lines within the surface. Magnetic field lines are like streamlines in a liquid stream, they realise something endless, and a separate purpose would give more or less lines. Many aspects have the result of performing magnetic field lines as though the field lines were natural events.