1. D, all of the above counts as communication
2. C, Domain Name Server translates domains into IP addresses
3. B, MAC addresses are physicall addresses of network interfaces
Subscript
Reference: Chapter 5 of 'An Object-Oriented Approach to Programming Logic and Design's by Joyce Farrell
I would have to say Effective Communication. Mainly because if everyone you have a team arguing over every option you are not focusing on one thing. This way you can discuss each option and have less of a divide if you all communicate what you feel effectively.
It could also be Leadership because as a leader you can avoid it completely and choose for your team. However based on what they are asking I still believe it would be B.
I only answered this question with this sentence,just so I can ask more questions to get answers.