Which of the following features is associated with the 13D?

The correct answer highlights the unique characteristics of the 13D model, particularly its absence of magnification alongside an LCD display. This feature indicates that the 13D is designed for users who prefer a sighting system that offers a clear view of the target without any magnification, making it ideal for fast target acquisition at close ranges.

The LCD display is integral as it provides a user-friendly interface and clarity under various lighting conditions, ensuring that operators can use the sight effectively in different environments. This design philosophy aligns with the operational needs where situational awareness and rapid response are critical, particularly in dynamic settings.

The other choices describe features that may be found in different models. A single illuminated dot is a simpler reticle design that may not specifically pertain to the 13D. A 4.5x magnification suggests the presence of a telescopic sight, which conflicts with the claim of no magnification. Lastly, while a weight of 2.9 lbs could apply to various optics, it's inconsistent with the lightweight and user-friendly intent of the 13D, which emphasizes portability and ease of use.