Translation termination triggered by specific signals

Steps:

• Identify key termination events in translation: stop codon recognition and release factor binding lead to polypeptide release.
• Evaluate each option: determine which combinations include only valid termination causes.
• Exclude events unrelated to termination, such as initiation or elongation steps.
• Select the option matching the two core termination events.

Why D is correct:

• Termination requires a stop codon (event 2) and release factor binding (event 3), as per the standard ribosomal release mechanism in molecular biology.

Why the others are wrong:

• A includes event 1, which is typically an elongation step, not termination.
• B pairs event 1 (elongation-related) with event 2, omitting the essential release factor.
• C pairs event 1 (non-termination) with event 3, missing the stop codon trigger.

Not enough information on exact events 1–3, but based on standard biology, D fits.

Final answer: D