Rewrite the following sentence by changing its voice (Passive/Active voice):

We made him leader.

The correct option is A He was made leader by us.

A sentence is in the active voice when the subject performs an action.

A sentence is said to be in the passive voice when the subject receives an action.

The given sentence is in the active voice. If this sentence is changed to passive voice, then the subject is also changed, in order to retain the meaning of the sentence.

So,

'Subject (we) + verb (made) + object (him) + object complement (leader)' changes to:

'New subject (He) + verb (was made) + object complement (leader) by + new object (us)'

The passive form of 'made' in the simple past tense is 'was/were made', the subject pronoun 'we' becomes the object pronoun 'us' and object pronoun 'him' becomes the subject pronoun 'he'.

This can be seen in option A, hence it's the right answer.

Option B: The verb form 'maded' does not exist.

Option C: The verb form 'made' is in active voice, without the helping verb 'was'. But, the form has to change while changing the voice.

Option D: The object 'by us' is missing here, and it changes the meaning of the sentence, by eliminating the object.

Hence options B, C and D are incorrect.