You determine that a trait has become common in a population as
a result of selection for that trait. Now you want to identify
whether the form of selection involved was natural selection,
sexual selection, or artificial selection. Which of the following
is an appropriate question to ask?

A. Did some individuals reproduce more than other
individuals?

B. Was a chance-event involved in selection for this trait?

C. Did the trait enter the population as a result of migration,
or a mutation?

D. Is the trait located on a sex chromosome?

E. What factor determined which individuals reproduced the
most?