OPTION "A" is the correct answer.
EXPLANATION:
There are two types of articles:
DEFINITE ARTICLE (THE) : Article 'the' is used to refer to a DEFINITE thing or person.
INDEFINITE ARTICLE(A/AN): Article 'a/an' is used to refer to a thing or person in general. For instance: man, door etc.
Article 'a' is used with consonant sounds whereas article 'an' is used with vowel sounds.
In the first blank, "zero article" or "no article" will be used because 'no article' is used before the name of week days. For instance - Monday, Tuesday etc.
In the second blank, "no article" or "zero article" will be used because 'no article' is used to refer to a particular/usual routine.
In the third blank, it is specifically mentioned that speaker is talking about " Sunday papers", hence, article "the" will be used.