Samantha and her friends Gabriel, Fabiana, Miguel, and Johnny are all taking an online algebra class. Currently, Samantha has completed 6/15 of the material in the course. Gabriel has completed 3/8 of the course, Fabiana 8/20, Miguel 5/10, and Johnny 9/21. Which of Samantha's friends has completed the same amount of the course as she has?

Select one:
A. Gabriel
B. Fabiana
C. Miguel
D. Johnny