Fill in the blanks with the most appropriate words.
A verb is used to express an occurrence, action, or state. It is the grammatical center of the predicate in a sentence.
An auxiliary verb is a verb which gives is used in the formation of tenses, moods, tones, etc.
Option D is correct as the given passage is in the passive voice and is about something in general. Therefore, only simple present tense in the passive form can be used.
The other options are wrong as no other tense can be used here.
The correct answer is D)is paid/are published/is sent