Answer:
North
Explanation:
In an electromagnetic wave, the direction of the wave, the direction of the electric field and the direction of the magnetic field are all perpendicular to each other.
Therefore, we can find the direction of the magnetic field by using the right hand rule. We have:
- Index finger: direction of motion of the wave --> toward the center of Earth
- middle finger: direction of the electric field --> west
- thumb: direction of the magnetic field --> north
So, the magnetic field points north.
There is too much information given, it's hard to understand exactly which variables are important in this problem.
Water that flows across the surface is called a;
Runoff
That's when rain has saturated the ground to the point it cant hold anymore and it runs over the surface.
The force exerted by the magnetic in terms of the magnetic field is,

Where B is the magnetic fied strength and F is the force.
Thus, if the magnetic A has twice magnetic field strength than the magnet B,
Then,

Thus, the force exerted by the magnet B is,

Thus, the force exerted by the magnet B on magnet A is 50 N.
The force exerted by the magnet A exerts on the magnet B is exactly 100 N as given.
Hence, the option B is the correct answer.