A. Suppose a CD player tries to detect whether its partner is CD player instead of a DD player, by looking for external signals that are at least as typical for DD players than for CD players. Draw a diagram to explain how two boundaries bL and bH are optimally determined. Show on the diagram where it is optimal to respond C versus D. Also explain what happens to the boundaries when detection becomes more cautious by raising the minimum likelihood ratio.

B. What is the meaning of the LDD detection strategy ?

C. What is the main problem with a detection strategy of looking for "truth-telling" signals from CD players?

Explain how the LDD strategy overcomes this problem