What is the primary danger of driving a motorcycle through thick dust storms (Haboobs) in arid Afghan provinces?

1. Visibility drops to zero within seconds, and airborne dust impairs breathing and coats visors, making obstacles and drop-offs invisible
2. The main risk is engine damage, so the rider should continue and have the machine serviced later
3. Riding faster clears the dust cloud sooner and is therefore the safer response
4. Stopping in the traffic lane with hazard lights on is the correct action