What color of an object that reflects all colors of sunlight

That would be the color white. It is due to all the colors being reflected equally. To see colors we are actually seeing the color that is being reflected by the object while others are absorbed. 

White i hope this helps have a wonderful day

The method used above involves the determination and comparison of the genes of the three species of finches. So, the answer is
(3) Obtain molecular evidence from all three species and identify similarities.
The genetic makeup of the three species will show different similarities that can be used to relate the evolution of the different species.