If you rub flea dirt on white paper, it will have a reddish-brown color. Why is this?
Interaction with Paper Fibers
When the dirt is rubbed on the paper, the dried blood particles in the dirt come into contact with the fibers of the paper. This interaction causes the color of the dirt to transfer onto the paper, resulting in a reddish-brown color.
It is important to note that if the dirt did not contain blood, or if the paper did not have fibers to interact with the dirt, the color change would not occur. Option C.