"D.all of the above" is the answer
It is because the “building” word that denotes infrastructures is a gerund. Gerunds are nouns that came from verbs + a suffix “ing". So in this case, “building” comes from the verb “built" (which implies that something is already done building something) + the “-ing”.
The use of hot water and soap does not belong to this protocols.
Breathing as moisture goes out of your mouth and though sweating but it is not here
