Alice wants to find out whether her pet gecko finds its prey based on vision. She thinks that her gecko will more easily see the colored crickets. She follows these steps:
1) Get 10 similar crickets from the pet store
2) Tag 5 of the crickets by putting a tiny dab of bright coloring on their backs
3) Release all 10 crickets into the terrarium with the gecko at the same time
4) After several hours, record the number of tagged and non-tagged crickets still alive in the terrarium
After several hours, Alice notes that only 4 non-tagged crickets were still alive in the terrarium. No tagged crickets were observed. She concludes that her gecko uses mostly its vision to capture and eat its prey.

What is another possible explanation for these results?
A.
The gecko only eats crickets that have a certain bright color.
B.
The crickets should have been introduced at different times.
C.
The cricket was attracted to the scent of the coloring.
D.
The gecko prefers other species of crickets to the one Alice used.