Step 1: General rule regarding character evidence.
Section 49 of the Bharatiya Sakshya Adhiniyam, 2023 governs the admissibility and relevance of character evidence in criminal proceedings.
Step 2: Position of bad character.
As a general rule, the bad character of the accused is irrelevant and cannot be used against him to establish guilt.
Step 3: Exception when good character is pleaded.
If the accused introduces evidence of good character, the prosecution is permitted to rebut it, thereby making bad character relevant.
Step 4: Conclusion.
Therefore, the correct answer is (D) irrelevant, relevant.