How does the dog's brain integrate information for smell while following the scent of a jackrabbit?
1) It combines the scent with visual cues to track the jackrabbit.
2) It uses its olfactory receptors to detect and process the scent molecules.
3) It relies on its memory to recognize the scent of the jackrabbit.
4) It analyzes the frequency and intensity of the scent to determine the direction of the jackrabbit.