Answer: C)Not excludable and rival in consumption.
Explanation: Not excludable is the situation where the permission of not using any resource or facility is prohibit that is it can be used without stoppage. Rival is defined as good that if some person uses it then other cannot use it at same point of time.
Local park which is completely occupied by the people for picnic is non excludable because it can be used by public without any kind of prohibition and rival because it is fully filled with people,so when they leave the park then only other public people can occupy it.Thus the correct option is option (c).
