The correct answer is option 3: Magnetism.

Factors that affect the direction of wind are often related to atmospheric processes and the Earth`s rotation.

Option 1: Pressure gradient refers to the difference in pressure between two points in the atmosphere. Air flows from regions of higher pressure to regions of lower pressure, creating wind currents.

Option 2: Friction plays a role in slowing down the movement of air near the Earth`s surface. This can cause the wind direction to deviate from the expected flow based on the pressure gradient alone.

Option 4: The Coriolis effect is a result of the Earth`s rotation. As air moves horizontally from high to low pressure, it gets deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This deflection influences the direction of wind.

Option 3: Magnetism, on the other hand, does not directly affect the direction of wind. While magnetism plays a role in various natural processes, it does not have a significant influence on the movement of air masses or wind patterns.