In the sentence, the word 'has' indicates that the tense of the sentence is present tense. Also, the main verb 'paid' is in its participle form and since this form can only be used for perfect tenses, the tense of the sentence is present perfect tense. Thus, the answer must also be in present perfect tense.
Option A is incorrect. 'earned' is itself a main verb. Since the sentence already has a main verb, introducing another verb will make the sentence grammatically incorrect.
Option B is incorrect. 'being' indicates a continuous tense and does not indicate a perfect tense. Thus, using it will make the tense of the sentence inconsistent.
Option C is correct. 'been' is in the present perfect tense. Thus, it has the correct tense and is the correct answer.
Option D is incorrect. 'been earning' will introduce a second main verb 'earning' in the sentence. Also, it indicates a continuous tense and not a perfect tense. For above reasons, it is incorrect.