Select the option that expresses the given sentence in passive voice.
All his friends laughed at him.

Correct option is B

Active Voice- It denotes that the noun or pronoun that acts as the subject in the sentence is the doer of the action. In other words, the subject performs the action or acts upon the verb.
Passive Voice- represents that the subject is one acted upon by the action or verb in the sentence. It can also be said that the passive voice indicates that the subject in the sentence is no longer active but passive.
 The sentence is an example of active voice having form:
 Sub + V₂ + obj.
 When it is converted into passive voice, following rule must be followed:
 Obj. + was/were + V3 + by + obj.