Answer the following questions about CSMA (3-5 sentences each):

2.1 For Carrier Sense Multiple Access, how does the CS threshold impact spatial reuse and interference?

2.2 Explain the hidden and exposed terminal problems with an example.

2.3 Why is it difficult to use CSMA-CD in the wireless medium?

2.4 Using only physical carrier sense, can you avoid the hidden terminal problem? If so, how? If not, why?

2.5 Could there be problems with using only virtual carrier sense and no physical carrier sense?