The type of channel that speaker one and speaker two use in their communication would be auditory - b.
The fact that we're talking about "speaker" 1 and "speaker" 2 implies already the fact that both of them are talking and this then implies that they are using the auditory channel of communication.
The president must be a natural-born citizen of the United States, be at least 35 years old, and have been a resident of the United States for 14 years.
The native Americans already had the first 3 items. The British brought horses to the new world and the native Americans used them a good bit Civil War and after.