What happens when new data call current scientific explanations into question

"acknowledging a right to benefit from the presence of animals requires government action to ensure human access to animals in a number of different spheres," writes jessica pierce, ph. d., in psychology today. the pragmatic meaning of the term "right" in this statement is

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a. one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b. one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c. one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.

2. which is the last step in the scientific method?