Mary sees Greta trip while walking down an outside flight of steps, and thinks to herself, "What a clumsy person!" Five minutes later, though, Mary trips on the same flight of steps, and says to an onlooker, "It's very icy today!" This is an illustration of the:

This is an illustration of interchannel discrepancy during deception

Explanation:

Interchannel discrepancies are a type of nonverbal cue that can signify deception. They are nonverbal cues and body language that are inconsistent with each other. An example is a person who is properly controlling their facial expressions (hiding deception) but are not looking you in the eyes (which signifies deception). The inconsistency of interchannel discrepancies can betray the person and signify that deception is occurring

explanation:

with the profits from the european sales, merchants purchased europe's manufactured  goods, including tools and weapons. then the merchants shipped those manufactured  goods, along with the  american  sugar and rum, to west africa where they were bartered for  slaves.

i would say b. research typically uses a variety of sources