Briefing Cloudera Knowledge

What is the most common reason for a k-means clustering algorithm to returns a sub-optimal clusterin

What is the most common reason for a k-means clustering algorithm to returns a sub-optimal
clustering of its input?

A.
Non-negative values for the distance function

B.
Input data set is too large

C.
Non-normal distribution of the input data

D.
Poor selection of the initial controls