Determine whether the sampling is dependent or independent. Indicate whether the response variable is qualitative or quantitative.
A psychologist wants to measure the effect of music on memory. He randomly selects 80 students and measures their scores on a memory test conducted in silence. The next day he measures their scores on a similar test conducted while classical music is playing. The mean score without music is compared to the mean score with music.
A. quantitative, independent.
B. ​quantitative, dependent.
C. ​qualitative, dependent.
D. ​qualitative, independent.