Questions: Private goods are both a. nonexcludable and rival in consumption. b. excludable and rival in consumption. c. nonexcludable and nonrival consumption. d. excludable and nonrival in consumption.

The answer is b. excludable and rival in consumption.

This option describes common resources, not private goods. Common resources are rival in consumption because one person's use diminishes another person's ability to use it, but they are nonexcludable because it is difficult to prevent people from using them.

This is the correct description of private goods. Private goods are excludable, meaning that people can be prevented from using them if they do not pay for them. They are also rival in consumption, meaning that one person's use of the good reduces the amount available for others.

This option describes public goods. Public goods are nonexcludable, meaning that it is difficult to prevent people from using them, and nonrival in consumption, meaning that one person's use does not reduce the availability for others.

This option describes club goods or toll goods. These goods are excludable because people can be prevented from using them if they do not pay, but they are nonrival in consumption because one person's use does not reduce the availability for others.