Steel anticorrosion study. Researchers at the Department of Materials Science and Engineering, National Technical University (Athens, Greece), examined the anticorrosive behavior of different epoxy coatings on steel. (Pigment & Resin Technology, Vol. 32, 2003.) Flat panels cut from steel sheets were coated with one of four different types of epoxy (S1, S2, S3, and S4). After exposing the panels to water for one day, the corrosion rate (nanoamperes per square centimeter) was determined for each panel.

A. What are the experimental units for the study?
B. Suppose you are interested in describing only the corrosion rates of steel panels coated with epoxy type S1. Define the target population and relevant sample.