Answer:
A) market basket analysis.
Explanation:
Based on the information provided within the question it seems that the technique that HairCare is using in order to cross-sell its products is called Market Basket Analysis. This is a technique used with the belief that if an individual buys a certain product they are more likely to buy another set of specific products that are gathered from data of other people who have purchased the product alongside other items. Like HairCare is doing by having a "Customers Who Bought This Item Also Bought" section.
