You should perform this prior to all hair services

• A. Post-shampoo residue
• B. Conditioning test
• C. Scalp examination
• D. Hair analysis

Answer: (D)

Beginning with a thorough hair and scalp analysis is essential before any service. This evaluation looks at the hair’s texture, porosity, elasticity, density, and overall integrity, as well as the scalp’s health and condition. With this information, you can choose the right products, determine appropriate processing times and strengths for chemical services, and plan protective measures to minimize damage. It also helps you spot issues that may require postponing a service or referring the client for medical care.

The other checks are narrower in scope. Post-wash residue is something you assess after cleansing, not before a service. A conditioning test shows how hair responds to conditioner but doesn’t provide the full picture needed to plan a service. A scalp examination is important, but hair analysis combines scalp and hair shaft assessment for a complete picture. That broader assessment is why hair analysis is the best pre-service step.