Active and Passive Voice Questions

In the following question, a sentence has been given in Active/Passive voice. Out of four alternatives suggested, select the one which best expresses the same sentence in Passive/Active voice.
The seawater eventually corroded the pillars of the bridge.

Select the option that expresses the given sentence in active voice.
Let the children be given enough time to read.

Select the option that expresses the given sentence in active voice.
"The parcel could have been misplaced by the delivery boy."

Select the option that expresses the given sentence in passive voice.
People say that she is a kind lady.

A sentence has been given in Active/Passive Voice. Out of the four given alternatives, select the one which best expresses the same sentence in Passive/Active Voice.
A hunter whipped the bear.