Narendra works from home and relies on email for his work. He is growing very frustrated by unsolicited marketing emails (spam) that he is receiving in larger and larger quantities every day. The emails are sent by Namira to advertise her company "Very Good Building Co."

Select the item from the list provided to make the following statements true.

	Namira's sending of many spam emails results in the processing of email being __________.
	Email systems under these conditions are an example of a __________ good.
	Namira's overuse of the email server to the disadvantage of Narendra and others is an example of __________.

1.	> 0
2.	Common
3.	Collective
4.	Binary category
5.	Tragedy of the Commons
6.	Non-rivalrous
7.	Excludable
8.	Rivalrous
9.	Private
10.	0
11.	Public
12.	Spectrum