I __________ never __________ such a beautiful place.

The correct answer is A: have / seen. This sentence requires the present perfect tense, which is used to describe an action or state that occurred at an unspecified time in the past and has relevance to the present, or an experience that has happened up to now. The present perfect is formed using 'have' or 'has' followed by the past participle of the main verb. Since the subject is 'I', we use 'have'. The past participle of 'see' is 'seen'. The word 'never' is a common adverb used with the present perfect to indicate that an experience has not occurred at any point up to the present moment. Therefore, 'I have never seen' correctly conveys the meaning of not having experienced seeing such a beautiful place before. Options B, C, and D use incorrect auxiliary verbs, incorrect forms of the main verb, or an inappropriate tense for describing a past experience with present relevance.