Answer:
A joke was told by Seema.
Step-by-step explanation:
In the rewritten passive sentence above, Seema who was the subject of the given sentence becomes the object. This is how passive sentence are phrased. Instead of the subject to perform an action on the object, the subject rather receives the action and the object assumes the position of the subject.
Therefore, while the first sentence- "Seema tells a joke," is in the active voice, the sentence, "A joke was told by Seema," is in the passive voice.