Concept:
To convert active voice into passive voice, make the object the subject and adjust the verb using the correct tense.
Explanation:
The active sentence is in present simple tense (“lights”).
In passive voice, present simple becomes: \textit{is + past participle}.
The object “the lamp” becomes the subject, and “she” becomes “by her.”
Thus, the correct passive form is: The lamp is lighted by her.