Select and explain an appropriate method of electronic data communication for the following situations:

1. Centaur Ltd wishing to advertise and sell its products.
2. An employee of the company wishing to update their manager on their work and receive advice on how to do various tasks.
3. An employee living in a remote area wishing to upload and download documents from the company website
4. An employee living in a city in the UK wishing to have high speed access to the Internet.
5. An employee needing to work from home but still have access to the Centaur network.