Answer:
<em>IAU- International Astronomical Union</em>
Explanation:
The International Astronomical Union (IAU) is an organization consisting of professional astronomers from around the whole world. The astronomers in the International Astronomical Union (IAU) work together to assign names and probable functions of different celestial bodies being discovered. The aim of the International Astronomical Union (IAU) is to protect and to safeguard field of astronomy and make progress in this field.
Answer: C
Explanation: Left ventricle. With the thickest muscle mass of all the chambers, the left ventricle is the hardest pumping part of the heart, as it pumps blood that flows to the heart and rest of the body other than the lungs.