What is the required time for thrust reversers to actuate for cold-soaked aircraft?

The required time for thrust reversers to actuate for cold-soaked aircraft is 2 seconds or less. This specification is crucial because aircraft that have been exposed to very low temperatures may experience slower actuation times due to the potential for ice or other factors affecting the mechanism. Ensuring that the thrust reversers engage within this time frame is vital for maintaining control during landing, especially on slippery surfaces where timely deceleration is necessary to prevent overshooting the runway or encountering adverse runway conditions. While the other options suggest different time limits, it is the 2 seconds or less threshold that aligns with operational safety standards and ensures effective performance in cold-soaked conditions.