Which of the Following Is Not a Procedure to Check

Which of the following is not a procedure to check the quality of clustering results?

A) Split the data randomly into halves. Perform clustering separately on each half. Compare cluster centroids across the two subsamples.
B) Delete variables randomly. Perform clustering based on the reduced set of variables. Compare the results with those obtained by clustering based on the entire set of variables.
C) Use the same method of clustering and compare the results.
D) Perform cluster analysis on the same data using different distance measures. Compare the results across measures to determine the stability of the solutions.