$[$ From in$-$class discussion: weeks $4,5]$ Which statement is FALSE regarding unsupervised learning:

An example of unsupervised learning is the Netflix content recommender system.

Unsupervised learning involves using a test dataset with labeled cases to validate machine learning performance.

Unsupervised learning is best suited for massive amounts of unlabeled data that has many dimensions$/$features$.$

In unsupervised learning, various types of clustering algorithms are used to extract relationships among the input data.