Given the rationale, provide a reasonable question and answer. Step-by-step reasoning process: Male dogs use pheromones in urine to mark their territory. Generally, pheromones are volatile substances. Male dogs use volatile substances in urine to mark their territory.
 The question and answer:
user
Male dogs use what in their urine to mark their territory?
Options:
- (A) hydrocarbons
- (B) volatile substances
- (C) kinetic energy
- (D) an area swollen with pus
- (E) Chemical energy
- (F) competing for resources
- (G) add a solute
- (H) Positive charges
The answer is (B)
assistant