Q:Fact 1: Male dogs use pheromones in urine to mark their territory. Fact 2: Pheromones are a sub-category of semiochemicals. Given the two facts above, answer the question "Male dogs use_ in urine to mark their territory." with the following options: - ammonia - Chemical energy - proteins - semiochemicals - animals - heat produced - nitric oxide - They have thick fur
A:
semiochemicals