Step 1: Understanding the sentence.
The given sentence is in direct speech:
He said, “I have passed the examination.”
The reporting verb said is in the past tense.
Step 2: Rule of reported speech.
When the reporting verb is in the past tense, the tense of the reported clause usually changes to its corresponding past form.
Present perfect tense (have passed) changes to past perfect tense (had passed).
Step 3: Analyzing the options.
(A) correctly changes “have passed” to “had passed” and follows proper reported speech rules.
(B) does not correctly shift the tense.
(C) keeps the tense unchanged, which is incorrect here.
(D) changes the meaning completely.
Step 4: Conclusion.
Therefore, the correct reported speech is option (A).