The correct answer is "Each person, regardless of age or backgrounds, has the right to krump." 'Has' is a third person singular form of the verb 'have.' This means that it will be used in a sentence where the subject is another person (not yourself.) In this case, the subject is "person," which is singular and not yourself. What if the subject of this sentence was "people" instead of person? We would use "have" because the subject is now plural!
"C. shall be coming" is the only future progressive verb form from the options listed. The other options are either past, present, or future perfect.
