5. According to the textbook, which of the following statements is (are) correct? (x) Oil is found in large pools underneath the surface of the earth and ownership rights to the pools are often unclear. As such, oil could be considered a common resource because it is nonexcludable and when one landowner uses a well to extract oil, less is available for the other landowners above the pool of oil. (y) When one person uses a common resource, it is difficult to charge him or her for usage of it and since a common resource is rivalrous, other people are usually not as well off. (z) When one person uses a common resource, a negative externality is typically eliminated because that individual person was able to enjoy the good. A. (x),(y) and (z) B. (x) and (y) only C. (x) and (z) only D. (y) and (z) only E. (x) only.