Final answer:
In preparation for a chemical relaxer, one must assess porosity, elasticity, and density of the hair, but not the scalp condition. The hair matrix specifically contains a layer of basal cells.
Step-by-step explanation:
When analyzing the hair before a chemical relaxer, it is necessary to evaluate several aspects of the hair to determine its suitability for the process. However, the option that is not necessary to evaluate is Scalp condition. The correct aspects to look at are a) Porosity, b) Elasticity, and c) Density. These factors determine how the hair will react to the chemicals used in the relaxer process.
To answer the specific reference question, the hair matrix contains d) a layer of basal cells. The hair matrix is a layer at the base of the hair follicle that is responsible for the production of new hair cells. The basal cells in the matrix divide and push older cells upwards, forming the hair shaft.