Answer:
a conditioned stimulus
Explanation:
Ivan Pavlov was a great psychologist who has discovered the theory of classical conditioning while experimenting with dogs and has given a few important terms in the theory including conditioned and unconditioned stimulus and response.
Conditioned stimulus: According to Pavlov's experiment on classical conditioning, the term conditioned stimulus is defined as a formerly neutral stimulus after getting connected with an unconditioned stimulus gives rise to a conditioned response.
In the question above, the statement signifies that the sound of the bell is a conditioned stimulus.
I would say B. Rivers provided a source of both water and transportation.
This would have to be true, as the great amount of waterways connecting the region would allow for transportation and a supply of water.
Sara is probably unpopular.
In general, people acted silly in front of their peers in order to gained attention from their social group.
Combined with the fact that Sara is insensitive to her friend's feeling, we could conclude that Sara is not received very well among her social groups despite her efforts to gained attention.
The answer is "conflict theorists".
Conflict theories are viewpoints in sociology and social psychology that accentuate a realist understanding of history, rationalistic technique for examination, a basic position toward existing social plans, and political program of unrest or, in any event, change. Struggle hypotheses attract consideration regarding power differentials, for example, class strife, and for the most part differentiate generally prevailing belief systems.