You are an ML engineer at a global shoe store. You manage the ML models for the company`s website. You are asked to build a model that will recommend new products to the user based on their purchase behavior and similarity with other users. What should you do? 

Answer options:

A. Build a classification model
B. Build a knowledge-based filtering model
C. Build a collaborative-based filtering model
D. Build a regression model using the features as predictors

C

Reference: https://cloud.google.com/solutions/recommendations-using-machine-learning-on-compute-engine