You are presented with the question "What do dogs use to mark their territory?" and the following answer choices: 
- water
 - Chemicals
 - layers of fat
 - food
 - Animal fur
 - heat energy
 - Scratches
 - heat produced

Now knowing that male dogs use pheromones in urine to mark their territory and pheromones are a sub-category of semiochemicals, choose the best answer.


 

  Chemicals       