Because the above sentence is in Simple Present tense. It's structure is - Subject+V1/V4 +Object.And also Subject is singular therefore it's verb would also be singular.
Correct option is C because '''My Father ''' is singular and the rule is if the subject is singular then the verb must be pural . So here the subject is singular so the answer must be in pural .
Buys . because if we read the sentence carefully so as sentence the last word is everyday ..which means his father buys newspaper daily basis ..and it is also suitable for the sentence..
C because his father buys the newspaper on a daily basis which makes it simple present but on a serious note this a very easy question not judging or anything but to me ya easy