The correct option is
D Never
'Adverb' is a word which modifies the meaning of a verb, adjective or another adverb. In the first sentence, the verb is "have been'. The word 'never' modifies the meaning of the verb, 'have been'. Hence, it is an adverb. As i
t makes the verb negative, it is called an adverb of negation. Hence, option B is correct.
Option A: The word, 'would' is a modal or a helping verb, which indicates the possibility of 'going there'.
Option C: The word, 'have' is an auxiliary or helping verb, which is a part of the verb, 'have been'.
Option D: 'Maldives' is a proper noun and not an adverb.
As 'would', 'have' and 'Maldives' are not adverbs, options A, C and D are incorrect.