Male dogs use_ in urine to mark their territory.
Options:
- (A) ammonia
- (B) Chemical energy
- (C) proteins
- (D) semiochemicals
- (E) animals
- (F) heat produced
- (G) nitric oxide
- (H) They have thick fur Let's be accurate as possible.
Male dogs use pheromones in urine to mark their territory. Pheromones are a sub-category of semiochemicals. Male dogs use semiochemicals in urine to mark their territory.
The final answer: (D).