It would be D because would be small and you wouldn't feel it. For answer A, the scientist could feel it. For answer B, you can kind of feel it or feel it. For C, It can definitely feel it. So the answer would be d.
Answer:
Most planets have an atmosphere but none has a hydrosphere like Earth does.
Explanation:
<span>The average human red blood cell is roughly 6 to 8 micrometers wide. The width of a pin is this problem is defined as 1000 micrometers. Assuming we use the smallest size of a blood cell, then we divide 1000 by 6, and we find that roughly 166.66 (or 166 if you are rounding down) red blood cells will fit.</span>
