I believe that D is the answer to your question, even though this is a complicated one.
The answer is <span>B. immune cells that are destroyed by HIV
CD4+ are immune cells (white blood cells) and are an important part of the immune system. Their name comes from the presence of CD4 glycoprotein on their surface. HIV uses CD4 glycoproteins on the surface of CD4+ cells to entry into the cells. The consequence is a reduced number of those cells. Therefore, CD4+ immune cells are destroyed by HIV.</span>
Answer:
Gravity is the main force responsible for mass movements. Gravity is a force that acts everywhere on the Earth's surface, pulling everything in a direction toward the center of the Earth. On a flat surface, parallel to the Earth's surface, the force of gravity acts downward
Explanation:
They carry oxygen to your entire body, and carry carbon dioxide away from your body to be exhaled.
