Marketing Cloud Personalization recipes are built using several types of ingredients (algorithms). The primary categories include Co-Occurrence (based on behavioral data like Co-Buy), Catalog-based (based on product attributes), Trending (based on overall popularity), and Promotions (for manually curated items). The options provided represent these distinct types.

B. Recommendations: This is the output or result of a recipe, not a type of ingredient used to build the recipe.

D. Machine Learning: This is the underlying technology that powers many ingredients, but it is not a category of ingredient itself.

1. Salesforce Help, Marketing Cloud Personalization, "Recipe Ingredients". This page details the different algorithms available as ingredients, which can be categorized into types such as Co-Occurrence, Attribute-based (Catalog-based), Trending, and Promotional Content.