Answer:
c. organizing observations into distinct groups based on a measure of similarity
Step-by-step explanation:
In the field of data science and machine learning, clustering is a technique that is used to identify sub-groups within a data set. This subgroups are called clusters because they share similarities. K-means is one technique of clustering where the algorithm iteratively tries to divide the data into a pre-defined K subgroup. k-means ensures that each data-point belongs to only one sub-group (cluster) and data-points in same cluster are as similar as possible.