Select the correct passive form of the given sentence.

How much will they pay you?

How much will you be paid by them?

The correct passive form of the given sentence "How much will they pay you?" is How much will you be paid by them?

The other options are incorrect because:

• How much will they be paying? is in the active voice, not the passive voice.
• Payment will be done by them? is grammatically incorrect. The verb "payment" is not a transitive verb, so it cannot take a direct object.
• They will have paid you how much? uses the future perfect tense, which is not typically used for questions.