Bohai and Adal Have Administered a Survey to a Sample

Bohai and Adal have administered a survey to a sample of college students to study the association between type of high school attended (public versus private) and social adjustment in college.They also considered the importance of students' socioeconomic background because that could affect the high school-college adjustment association.When all three variables are in the statistical model,the researchers observe a moderately larger adjustment score for students who attended public high schools,with a p-value of 0.03.These results tells Bohai and Adal that

A) there is only a small chance that the observed difference by high school is due to chance.
B) the null hypothesis can be rejected,but only for students who went to public high schools.
C) there is only a small chance that the sample is not representative of the college population.
D) socioeconomic background makes a 3% difference by high-school type.