Which one replaces the question mark? (2 marks) [Figure description: A symbol-transformation puzzle. An input string 'ABCD' passes through a four-diamonds-in-a-square symbol and then an 'H-shaped' symbol to give 'BCDX'. In the lower branch, from the first symbol, going down through the H-shaped symbol gives 'BCDX'. Another branch goes through an arrow-in-box symbol and then a filled-circle symbol to give 'XCD'. The question: ABC passed through the arrow-in-box symbol gives ?. Options: A: ABCX; B: CBA; C: ABCZ; D: AB.]
- A. ABCX
- B. CBA
- C. ABCZ
- D. AB