What happens during a tractor jackknife?
a.The trailer wheels lock and the trailer slides sideways
b.The tractor drive wheels lose traction and the rear of the tractor slides sideways toward the trailer
c.The front wheels lose traction and the tractor goes straight
d.The fifth wheel unlocks and the trailer separates
Explanation
In a tractor jackknife, the tractor drive wheels lose traction and the rear end of the tractor swings sideways. The tractor ends up folding toward the trailer, forming a V shape. This is usually caused by over-braking or driving too fast on slippery roads.