The answer is A. Crabs are more abundant in areas with high salinity than in areas with low salinity is a reasonable claim the researchers can make based on the data in the graphs.
Step-by-step explanation:
A) Crabs are more abundant in areas with high salinity than in areas with low salinity
This is a reasonable claim because the data in the graphs show that the average number of crabs per trap is higher in sites 1 and 2, which have the highest salinity levels, than in sites 3, 4, and 5, which have lower salinity levels. The claim is also supported by the error bars, which indicate the range of variation in the data. The error bars for sites 1 and 2 do not overlap with the error bars for sites 3, 4, and 5, suggesting that the difference in crab abundance between the high and low salinity sites is statistically significant.
B) Crab populations are most limited where salinity range between 10 and 15 psu.
This is not a reasonable claim because the data in the graphs do not show a clear relationship between salinity and crab abundance in this range. Site 3 has a salinity of about 10 psu and a low average number of crabs per trap, but site 4 has a similar salinity and a higher average number of crabs per trap. Site 5 has a salinity of about 15 psu and a low average number of crabs per trap, but site 2 has a higher salinity and a much higher average number of crabs per trap. The claim is also not supported by the error bars, which show a large overlap in the data for sites 3, 4, and 5, suggesting that the difference in crab abundance among these sites is not statistically significant.
C) Salinity does not influence crab populations because the number of crabs fluctuates across the five sites.
This is not a reasonable claim because the data in the graphs do show a general trend of higher crab abundance in higher salinity sites, as explained in claim A. The claim also ignores the possible effects of other factors that may influence crab populations, such as temperature, food availability, predation, and competition. The claim is too simplistic and does not account for the variability and complexity of the data.
D) Crab populations are larger in areas with low salinity than in areas with high salinity.
This is not a reasonable claim because the data in the graphs show the opposite trend, as explained in claim A. The claim is contradicted by the evidence and does not reflect the data.