Answer: The correct answer to the question is option A
THE CILIA ARE THE FIRST STRUCTURES INVOLVED IN OLFACTORY SIGNAL TRANSDUCTION.
Explanation: Cilia are organelles that is found in cells,they are hairlike in structure and they project to the outside is cells to help in mobility/locomotion in motile form and act as sensory organelles in non-motile form.
Example of places where cilia are found is the respiratory tract and female reproductive tract where they play a vital role in propelling foreign particles away from the lungs and propel the sperm in the direction of the uterus.
In olfactory signal transduction,the sensory cilia sends sensory impulse to the brain when smell isperceived especially that of food.