What is the first step in K-means to form k clusters?

a. Arbitrarily choose k objects as the initial cluster centers

b. Assign each object to its closest center

c. Find the closest center to each object

d. Update cluster centers based on only new members of the cluster

e. Update cluster centers based on both new and old members of the cluster

Which task is not part of data preprocessing?

a. Data integration

b. Data cleaning

c. Data transformation

d. Data reduction

e. Data generation