What must a private pilot applicant get from an authorized instructor before the knowledge test?

1. 1A signed letter that lists the topics of the test
2. 2A signed copy of the airman certification standards for the test
3. 3A logbook endorsement that the applicant is prepared
4. 4A written approval from the nearest FAA flight standards office

Source: 14 CFR Part 61, § 61.103 Eligibility requirements: General.