Economists believe that an activity should be continued up to the point where
a. the marginal benefit from the activity is equal to the marginal cost.
b. the marginal benefit from the activity is less than the marginal cost.
c. the marginal benefit from the activity plus the marginal cost equals zero.
d. the marginal benefit from the activity is greater than the marginal cost.

Email viruses are typically launched by people who modify header information to hide their identity. brightmail's enrique salem says that in the future, your email reader will authenticate the sender before putting hte message in your inbox. that way, you will know the source of all the emails you read. alan nugent of novell says, "i'm kind of a fan of eliminating anonymity if that is the price for security." will eliminating anonymity make computers more secure?

Heyak believed that the economy could be hard to measure because

Which of the following traits indicate that stephanie is good at time management in her new management role? during the work day, stephanie does not know what to do next. stephanie's work space is crowded and cluttered. stephanie uses breaks during work to see what friends are up to on social media. stephanie keeps a schedule for events, meetings, and deadlines.