According to Niko Tinbergen, Which Question Is Least Likely to Be

According to Niko Tinbergen, Which question is least likely to be addressed by basic studies of animal behavior? ​

A) Which mechanisms trigger a specific behavioral response? ​
B) What is the behavior's ecological function and how does it increase an animal's chances of surviving and reproducing?
C) How will the behavior be displayed after future evolutionary processes occur?
D) How does the expression of a behavior develop as an animal matures?
E) How did the behavior evolve?