Change the following from active to passive:

The research team will have reverified the samples before sunrise.

The correct option is The samples will have been reverified by the research team before sunrise.

To convert an active voice sentence into passive voice, follow these grammatical rules:

1. Identify the components of the active sentence:
- Subject: The research team
- Verb (Future Perfect Tense): will have reverified
- Object: the samples
- Time Expression/Prepositional Phrase: before sunrise

2. Swap the position of the subject and object:
- The object of the active sentence ("The samples") becomes the subject of the passive sentence.

3. Convert the verb structure into passive voice:
- The active verb structure for Future Perfect Tense is: will + have + past participle (V3).
- The passive verb structure for Future Perfect Tense is: will + have + been + past participle (V3).
- Applying this rule: "will have reverified" becomes "will have been reverified".

4. Add the original subject with 'by':
- "by the research team"

Combining all elements gives the complete passive sentence:
"The samples will have been reverified by the research team before sunrise."