Identify which one of these passages is an argument or explanation. Please also explain why you choose either argument or explanation for each:

Passage 1

Now the medical man who sees the patient only once a day or even only once or twice a week, cannot possibly tell this without the assistance of the patient himself, or of those who are in constant observation on the patient. The utmost the medical man can tell is whether the patient is weaker or stronger at this visit than he was at the last visit. I should therefore say that incomparably the most important office of the nurse, after she has taken care of the patient's air, is to take care to observe the effect of his food, and report it to the medical attendant.

Passage 2

To be "in charge" is certainly not only to carry out the proper measures yourself but to see that everyone else does so too; to see that no one either willfully or ignorantly thwarts or prevents such measures. It is neither to do everything yourself nor to appoint a number of people to each duty, but to ensure that each does that duty to which he is appointed. This is the meaning which must be attached to the word by (above all) those "in charge" of sick, whether of numbers or of individuals.