Select the correct passive form of the given sentence.
The negligence of the plant manager caused the mishap at LG Polymers.
1
The mishap at LG Polymers has been caused by the negligence of the plant manager.
2
The negligence of the plant manager was caused by the mishap at LG Polymers.
3
The mishap at LG Polymers was causing the negligence of the plant manager.
4
The mishap at LG Polymers was caused by the negligence of the plant manager.