C. Past Past perfect is defined as <span>something occurred before another action in the past. Example: I had my things packed before I went to Hawaii. She had studied all night before the last test.</span>
The correct answer is D, this is 'present perfect' tense. It is formed with the use of the verb HAVE in present simple tense (so, HAVE/HAS), and the past participle of a verb (or the third column of irregular verbs). A cannot be correct, because then it would say - I hear. B cannot be correct, because then it would say - I had heard. C cannot be correct, because then it would say - I heard. And since there is also HAVE HEARD, the correct answer has to be D.