Please answer both

Although digital storage costs have declined sharply in the past few years, many universities and companies still have limited storage space for email messages and impose a fixed limit on the amount of file storage space per user. Can we view this as a common property resource problem, and do the fixed limits resolve the problem? A. No, one person's use of the storage space does not have an impact on other people, so this is not a common property resource problem. B. Yes, the storage space used by one person is not available to another person, and the storage limit is a type of quota that allocates the property rights to the storage space. C. Yes, the storage space used by one person is not available to another person, and the storage limit represents a form of single-person ownership that resolves the common property resource problem. D. This is an example of a common property resource problem, but the fixed limits on storage space do not resolve the problem. The optimum level of pollution emissions A. occurs where no damage to the environment is being done. B. occurs where the marginal external benefit equals the marginal external cost. C. occurs where the marginal external benefit is zero. D. occurs where the marginal external cost equals the marginal cost of abatement. E. is zero