A researcher computed the average Math SAT score of all high school seniors who took the SAT exam for each of the 50 states. The researcher also computed the average salary of high school teachers in each of these states and plotted these average salaries against the average Math SAT scores for each state. The plot showed a distinct negative association between average Math SAT scores and average teacher salaries. The researcher may legitimately conclude which of the following? a. Increasing the average salary of teachers will cause the average of Math SAT scores to decrease, but it is not correct to conclude that increasing the salaries of individual teachers causes the Math SAT scores of individual students to increase
b. States that pay teachers high salaries tend to do a poor job of teaching mathematics, on average
c. States whose students tend to perform poorly in mathematics probably have a higher proportion of problem students and thus need to pay teachers higher salaries in order to attract them to teach in those states
d. The data used by the researcher do not provide evidence that increasing the salary of teachers will cause the performance of students on the Math SAT to get worse.