A professor assigns a massive homework set the first day of class that will be due the day the students walk in to take their first exam of the semester

Over the weekend he grades the homework and the exam papers and as he reviews the results, it occurs to him that students that worked more of the 40 problems in the homework assignment appeared to be more successful on the exam. Which of the continuous improvement tools would be most appropriate for displaying this phenomenon?
A) statistical process control (SPC)
B) scatter plot
C) Ishikawa diagram
D) Pareto chart

Answer: B