Why did the Soviets face greater resistance from the mujahideen than they expected?

Why did the Soviets face greater resistance from the mujahideen than they expected? Check all that apply.
The Soviets were unfamiliar with the Afghan terrain.
Arabs from many nations joined and enlarged the size of the mujahideen.
The Soviets’ poorly made weaponry was easily overcome and destroyed.
The mujahideen had an innate understanding of all the Soviets’ weaknesses.
The mujahideen received training and weapons from the United States.