If the goal is to identify the major factors underlying stock price fluctuations, ______ is likely the machine learning problem we want to address.

A. regression analysis
B. dimension reduction
C. clustering

Correct Answer: B

Dimension reduction focuses on reducing the number of features while retaining variation across observations to preserve the information contained in that variation. The purpose is to reduce the number of features under consideration, where each feature is a dimension that partly represents the objects.