What is One of the Independent Variables in the Peacock

Question

What is one of the independent variables in the peacock butterfly experiment?  
A) Presence of the wing spot
B) Range of migration
C) Species of bird predator
D) Experimental location
E) Percentage of survivors

Accepted Answer

The presence of the wing spot is a manipulated independent variable in the peacock butterfly experiment, as the researchers altered the presence or absence of the spot on the wings of some butterflies to see the effect on bird foraging behavior. The other options are either not manipulated (such as species of bird predator) or not relevant to the experimental hypothesis (such as percentage of survivors).