We can say that ,
Use structure “subject + auxiliary + past participle + by + object ”
The above given sentence is given in Passive Voice :-
I was told by somebody that there had been an explosion in the Town Hall.

Correct Option: D

We can say that ,
Use structure “subject + auxiliary + past participle + by + object ”
The above given sentence is given in Passive Voice :-
I was told by somebody that there had been an explosion in the Town Hall.
Hence , required answer will be option D .

We can say that ,
The above given sentence is given in Passive Voice :-
Use structure “auxiliary + past participle”
Will the truth be told us by her?

Correct Option: D

We can say that ,
The above given sentence is given in Passive Voice :-
Use structure “auxiliary + past participle”
Will the truth be told us by her?
Therefore ,required answer will be option D .

As per the given above sentence is given in Passive Voice.
Use structure “To + subject( object ) + auxiliary + past participle”
To resign was his obligation.

Correct Option: B

As per the given above sentence is given in Passive Voice.
Use structure “To + subject( object ) + auxiliary + past participle”
To resign was his obligation.
Therefore ,required answer will be option B .

Use structure “ Let + subject + auxiliary + past participle”
As per the given above sentence is given in Passive Voice.
Let me be not laughed at.

Correct Option: B

Use structure “ Let + subject + auxiliary + past participle”
As per the given above sentence is given in Passive Voice.
Let me be not laughed at.
Hence , option B will be required answer .

As per the given above sentence is given in Passive Voice.
Use structure “ Let + subject + auxiliary + past participle”
Let the poll results be looked at-is hope inspired by them?

Correct Option: D

As per the given above sentence is given in Passive Voice.
Use structure “ Let + subject + auxiliary + past participle”
Let the poll results be looked at-is hope inspired by them?
Hence , required answer will be option D .