Answer: A milestone
Explanation:
Based on the information given in the question, the answer is a milestone. A milestone simply tells the author that the work is gradually prigressing.
It is a finding which shows that a particular aim in the research plan has been achieved. Therefore, the correct option to the above question is D
If you aren't checking yourself then you may have a problem. For example you could have testicular cancer and you wouldn't know without feeling an unusual bump in that area.
All are possible physical changes
The answers that applly are
1. Kidneys Filter waste from Blood ( so the waste can be thrown out through urine)
2. Kidnesys reabsorb nutrients from the blood ( During the process of creating urine, so our body doesnt throw out important nutrients for our body)
3. Oxygenate blood ( kidney helps produce blood cells that could deliver oxygen)
Thats all.