Which of the following best defines the economic principle of a 'trade-off'? a. a trade-off is how much something costs. b. a trade-off is how important ant something is to the buyer. c. a trade-off is what you give up when you choose something else. d. a trade-off is the concept that with every decision, you get something and give something else up.

Which of the following statements is true about social anxiety disorder? social anxiety disorder tends to develop in early adulthood. social anxiety disorder often co-occurs with mood disorders and other anxiety disorders. social anxiety disorder is relatively rare, with a lifetime prevalence of about three percent in the united states. lesser than 30 percent of adults with social anxiety disorder report humiliating experiences that contributed to their symptoms.