Reaction time involves selecting a specific and correct response from several choices when presented with several different stimuli.
a. complex
b. standard
c. simple
d. visual

Simple reaction time involves selecting a specific and correct response from several choices when presented with several different stimuli. This is very important because historically, this was the first indicators of intelligence pioneered by Francis Galton. To measure one’s intelligence is to know how he quick a person could respond to the stimulus with an already expected response wherein the stimulus is given unknown to the receiver. In other terms, the intelligence is measured on how quick a person could grasp certain concepts and how he could think fast and answer them correctly.  

    5.5 n======    assuming that      we have      m = 0.145 kg    a = 38 m/s²therefore    5.51 n, but two significant figures.final answer: 5.5 n

Domain eukarya; kingdom plantae should be the answer.