<span>a. hyponatremia. is the answer
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The white lunar segment is called a "cuticle". It only real function is to help (minutely) with support and covering the nail.
What is this for if you don’t mind me asking
Huh? Please be more specific in your question
Seek help from medical staff present such as a resident nurse especially if the resident appears to be trying to hurt him or herself or expresses having suicidal ideations. Stay with the resident until help arrives. Also, it is good to try to get the resident to talk as much as possible to offer support, comfort and to diffuse the situation.