Here is your answer
D.
![<font color=](https://img.qammunity.org/2020/formulas/physics/middle-school/y6bpl5mf92wmotsywnivpjlw327jefw0su.png)
REASON :
A magnetic field is defined as the area where the influence of magnetic force can be experienced by placing a magnetic compass (deflection is shown in needle) or by bringing a charged particle near it.
The figure shows field lines around a bar magnet. At every point of field lines the magnetic force is experienced.
![<marquee>](https://img.qammunity.org/2020/formulas/mathematics/middle-school/vyqi8a2y5bmdpn1i3czkc5b9zqa68c9wz5.png)
HOPE IT IS USEFUL