B. Teenagers.
C. She doesn't want everyone to know what she does
D. 1.True. Justification : "Though video games were originally marketted for children.."
2. False. Justification : Kindle from Amazon caught on first adults..adult-only
3. True. Justification: Its growth has instead come from adults.
4. False. Justifcation: "Its growth has instead come from adults who might not have used a social network before Twitter."
E. -They already interact with friends via Facebook or text messaging
- They want to send longer messages.