Myra is working on her thesis for which she created a scatter plot of the number of teachers and the number of college graduates for cities in Australia. She noticed a positive correlation. Which of these do you think is the probable explanation for this correlation?
A: Teachers encourage people to go to college, so an increase in the number of teachers leads to an increase in the number of college graduates. 

B: Some college graduates choose teaching as a profession after graduating, so an increase in the number of college graduates also leads to an increase in the number of teachers.

C: There are more college graduates and teachers in higher income cities, so income is a confounding variable here, make it difficult to prove causation between number of teachers and number of college graduates. 

D: Cities with a higher population have more teachers and more college graduates, so the correlation is due to a third variable (population of city).

E: The provided data is insufficient, so it is extremely difficult to establish the reason for the correlation.

F: Most college students choose non-teaching professions after graduating, which explains the correlation. 

G: In Australia, college students are encouraged by their teachers to choose teaching as a profession after graduating.