I Notice That All the Students in My Class Seem

Multiple Choice

I notice that all the students in my class seem very drowsy 45 minutes into my class period.Knowing that it could not possibly be my lecture putting them to sleep,I consider other factors such as the fact that my class is at 5pm and the sun is usually setting at that time of the day,which I think may make people drowsy.What type of evidence am I collecting in making this observation?

A) experimental
B) anecdotal
C) peer reviewed
D) coincidental
E) untestable