Describe how you will tell your parents that Darshana was laughed at by all her classmates in active voice.

Correct option is A

Option (a) is the correct active voice of the given sentence.
Active Voice: In Active voice the subject is the one doing the action.
Passive Voice: In Passive voice the subject is the recipient of the action.
To convert active voice into passive voice the object becomes the subject and the subject becomes the object.
For Simple Past Tense as given in the question the structure for changing a sentence from active to passive and vice versa is:
(Active voice) Subject + V2+ object.
(Passive voice) Object+ was/were + V3+ by + subject.
The active voice is: "All her classmates laughed at Darshana."