All of the following are concepts in psychophysics except introspection. The correct option among all the options that are given in the question is the last option. Psychophysics actually deals with the relationship between sensations, perceptions and the physical stimuli that effect. It is a complicated but an important subject that has unlimited boundaries.
A is what I think why because I think it is the right answer
Vectors are used to measure the magnitude and direction of forces.
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