Select the correct passive form of the given sentence.
Mary Kom has won numerous boxing championships.

Correct option is B

The correct passive voice of the given sentence is (b) Numerous boxing championships have been won by Mary Kom.
Definition:
Active voice: The subject performs the action.
Passive voice: The subject receives the action.
Structure:
Active voice: Subject + has/have + past participle + object
Passive Voice: Object + has/have been + past participle + by + subject
Example:
Active: She has completed the task.
Passive: The task has been completed by her.
Here, “Mary Kom” is the subject and “numerous boxing championships” is the object, so passive voice will be:
“Numerous boxing championships have been won by Mary Kom.”