Select the correct passive form of the given sentence.
Karim is to kill the enormous black snake in the garden of his house.
1
The enormous black snake was to be killed by Karim in the garden of his house.
2
The enormous black snake has to be killed by Karim in the garden of his house.
3
The enormous black snake is being killed by Karim in the garden of his house.
4
The enormous black snake is to be killed by Karim in the garden of his house.