The correct answer among the choices given is option A. Eustachian, Pharynx, Bronchi are structures that ensembles a tube. The Eustachian tube is a narrow passage from the pharynx to the middle ear. Pharynx is a passageway leading from the oral and nasal cavities to the larynx and the esophagus. Lastly, bronchi is an airway in the respiratory tract.
I would radiation a robotics arm but for a heated surphace is Shiny surfaces are poor absorbers and emitters (but they are good reflectors of infrared radiation).
OKAY SO FIRST.... THE SUN IS IMPORTANT FOR PLANTS TO LIVE AND UMMM... SECOND IT PRODUCES LIGHT AND HEAT WHICH WARMS THE EARTH... AND LAST BUT NOT LEAST