Answer:
C. They send proteins as chemical messages
Step-by-step explanation:
In the case of Japanese beetles, the female is the one who attracts the pheromones that have a role in the mating. The pheromones are the chemicals that serve to get a social response from the same species.
The males, however, produce the protein that helps them discover the pheromones which afterwar is sent to the female with the goal of mating.