Thirty mechanics in an automotive shop are randomly selected to participate in a study comparing two oil changing techniques. They are randomly assigned one of the two techniques. The manager trains 15 mechanics on one technique and trains the other 15 mechanics on the second technique. He then records the number of oil changes each mechanic does in one week. Which inferential statistical test would be most appropriate for this scenario? A. A one-sample z-test B. A two-sample t-test C. A paired t-test D. A chi-square goodness-of-fit test E. A one-sample t-test