The given sentence is in the active voice, as the subject 'They' performs an action 'pay' against the object 'you'.
If this sentence is changed to passive voice, then the object takes the place of the subject and vice versa and the word
'by' is introduced as now the subject receives the action by the object.
The verb form of the sentence is also changed from active form to
passive.
'Question word (How much) + auxiliary verb (will) + subject (they) + verb (pay) + object (you)' changes to:
'Question word (How much) + auxiliary verb (will) + new subject (you) + verb (be paid) + by + new object (them)'
The
passive form of 'will pay' in the simple future tense is 'will be paid'.
This can be seen in option D, hence it's the right answer.
The auxiliary verb 'will' determines the tense and comes before the subject in interrogative form.
Option
A: The tense of the given sentence is in simple future, whereas here the verb
'are you paid' expresses the simple present tense.
Option B: Similarly, 'are they paying' expresses the present continuous tense whereas the sentence is in simple future tense.
Option C: 'Have they paid' is in the present perfect tense whereas the given sentence is in simple future tense 'will they pay'.
Hence options A, B and C are incorrect.