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.
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