Another transistor amplifier problem

[poala999]

http://www.vcaa.vic.edu.au/vce/studies/physics/pastexams/physicspilot12004.pdf

Page 13. AC signal on CRO. Answer is B. How the heck do they do that?

Relevant information is on page before.

Love peoples explanations but please try to keep it simple.

Sorry if i seem direct.

I don't understand why it is centred around 12V, and the cut off points.

Sub-question...? what would this look lke if there was a capictor on the Vout.

 

[poala999]

not sure if I'm allowed to post my msn address but here it is k.c@internode.on.net, add me for a chat if need be. Thanks a million!