You are presented with the question "What do male dogs use in urine to mark their territory?" and the following answer choices: 
- Natural aphrodisiacs
 - competing for resources
 - Tails
 - Urine  cleaner
 - Something coming from a gland
 - Chemical energy
 - an area swollen with pus
 - Chew toys

Now knowing that male dogs use pheromones in urine to mark their territory and pheromones are natural aphrodisiacs, choose the best answer.


 

 Natural aphrodisiacs        