Which step in centroid-based clustering assigns each data point to the nearest centroid?

• A. Allocation
• B. Initialization
• C. Recalculation
• D. Euclidean distance

Answer: (A)

In centroid-based clustering, you determine which cluster a point belongs to by finding which centroid is closest to that point. This assignment, or allocation, step uses a distance measure (commonly Euclidean distance) to compare the point to all centroids and assigns it to the nearest one. After all points are allocated, the centroids are updated by taking the mean of the points assigned to each cluster, and this process repeats until the clusters stabilize. Initialization sets the starting centroids, and the distance measure is the tool used to judge proximity, not the step itself.