Select the correct passive form of the given sentence.
They all know that they will have to pay the bill of electricity and water within fifteen days.
1
It is known to all of them that they will have to pay the bill of electricity and water within fifteen days.
2
It was known to them that they will have to pay the bill of electricity and water within fifteen days.
3
It was known that they will have to pay the bill of electricity and water within fifteen days.
4
It them that they will have to pay the bill of electricity and water within fifteen days.