Answer:
Case study.
Explanation:
The research of psychology are mostly based on the observation and experience of the individual. The psychologist must follows the proper rules and regulation of the research.
Dr, Smith research is based especially on the case study. These case study includes the collection of the data from the multiple source. The reaction of the individual is measured on the different visual sensation and different sounds. Quantitative data collection is mostly used in the case study of the Dr. Smith.
Thus, the answer is case study.
The answer is
Organ level.
This is why
the levels are Cell-Tissue-Organ-Organ system-Organism
During aerobic respiration, NADH delivers electrons to electron transport chain, and then oxygen captures electrons at the end and joins with hydrogen to form water