If male dogs use natural aphrodisiacs in urine to mark their territory, then what do male dogs use in urine to mark their territory?

Answer choices:
- Natural aphrodisiacs
 - competing for resources
 - Tails
 - Urine  cleaner
 - Something coming from a gland
 - Chemical energy
 - an area swollen with pus
 - Chew toys

 

 Natural aphrodisiacs         